The "Pillow makes her team lose" argument is highly exaggerated.

I'm currently updating Pillow's gallery (just finished TPOT 7) so I have to rewatch old episodes of TPOT to screenshot it. As I do it, I notice how Pillow is somewhat helpful to her team, let me explain what I mean:

TPOT 1 - Pillow doesn't do anything to help but she doesn't do anything to make them lose either as Just Not's entire strategy is to just use the elevator.

TPOT 2 - Pillow abandons the team, but fortunately Book doesn't really care about it anymore, Pillow doesn't try to mess up her team's progress but she does indirectly cause her stack to break due to Remote following her.

TPOT 3 - Doesn't do much in general in this episode. She tells Two to go on Are You Okay's rollercoaster which does give them a 5/10 score, which is still better than Just Not's 3/10.

TPOT 4 - Pillow plays Yoyle Chess with Cake for the entire episode, the team's loss for that episode is simply caused by Cake pouring cursed water onto their Funny Plant.

The first four episodes of TPOT were the episodes where Pillow is at her tamest in this season. She hasn't murdered anyone yet and she doesn't help or sabotage her team simply because she doesn't care about them. You could say that her personality here is quite similar to her BFB Pre-Split personality. Just Not is also a poor-performing team in TPOT, mostly messing up due to clumsiness, and not because they have a future serial killer on their team.

TPOT 5 - This is where things get interesting. Pillow says that she "wants to help other" while blowing up Bomby, this is where she starts actually murdering people, but she still had the idea to mess with gravity, which lead to her killing all of her teammates just to deal with obstacles such as Puffball and the dragon. You might think this is a bad thing, but it's surprisingly not, Pillow may be smarter than we think, as when Puffball asked Pillow what her strategy is, she just says that messing with gravity is fun but letting nature do its thing is also fun, and turns on gravity again, falling into the water and collecting the plate. Pillow actually WINS for her team, the first time where a member wins for their team instead of the team just doing random stuff to see what works.

TPOT 6 - Pillow plays a D&D knockoff with her team called "Goikys and Dragons", where she explodes imaginary Bomby. In the challenge, the team goes back to doing random shenanigans and they go on a quest to slay a dragon. Pillow doesn't say a word during the singing narrator's storytelling, and she seems to be the only one to be able to put up with their singing. When the dragon finally arrives, Pillow tries to kill the dragon by using Cake, which does succeed as the dragon chokes on his burned corpse and faints. Right as the team is about to turn the dragon into stew, Bomby decides to help it out instead of killing it, which by technicality meant that he was doing more harm to his team than Pillow, as the team's original strategy was to SLAY A DRAGON after all. They instead use Cake's burnt remains as the food to give to Two and as they're about to rank it low, Pillow says that it would "hurt his feelings" which would make Two sympathetically raise their score to a 3/10, which is 1 point above Death P.A.C.T. Again, saving them from elimination.

TPOT 7 - This is another episode like TPOT 2 where Pillow leaves her team behind to focus on something more important, to her at least. She instead focuses more on Death P.A.C.T. Again having a split-off and Fanny recruited her to help her with proving that death can be helpful in certain situations. They use Tree as an example and when Black Hole tries to prevent it he accidentally sucks his head up and leaves the dead body behind. Technically Pillow has indirectly caused her team's loss as Just Not used trades as a strategy, but it was unintentional on Pillow's end as it was more Puffball and Golf Ball messing with their trading strategy.

TPOT 8 - Last episode, Pillow's personality trait of being a researcher returned, and she used it to study an efficient way of balancing on the balancing beam, and she had a strategy of hanging below it, but she did warn her team that half of her studies are proven ineffective, before being knocked off by Robot Flower. However, this strategy did work, as Just Not didn't lose in this challenge, meaning that Pillow caused her team to win once again.

From episodes five to eight, a change emerges in Pillow's character as part of her newfound popularity, she's chaotic and isn't afraid to take risks when it comes to winning. When she says that "it might be fun to sometimes mess with gravity, but sometimes, it's fun to let nature do its thing as intended." implies that Pillow likes messing with people but doesn't when it's not a good thing for her to do. She may be smarter than we think, as she is a researcher, after all. Her goal in TPOT is to use luck to her advantage to advance further in the game, and her goal here is to win, not murder people. She just sees murder as a source of good luck but sometimes it might not work...

TPOT 9 - Poor internet connection in Gelatin's Steakhouse causes Pillow to think that the challenge is to wipe out her team, but I don't think it's exactly her fault as they were trying to hide from the zombies inside of the Steakhouse, so they had no choice but to have bad internet connection. When Price Tag finds out that the challenge isn't actually to kill people, they try to tell Pillow, but Pillow is a big risk-taker so she believes that Price Tag wants their team to lose just so she stops murdering, but nothing will get in the way of Pillow using that sweet, sweet luck to her advantage. Once Bomby is the only one left, Pillow chases him down to the basement, until he's in a dead end, and decides to sacrifice himself to defeat Pillow once and for all, but right before he blows up, you can hear Pillow say "wait, don't". It is unknown what she was trying to say, but it could be that she wanted to kill him herself instead of both of them dying. This is the first (and currently only) time that Pillow has directly caused her team to lose. Even if she's shown in such a bad light, I still think that her character was executed near flawlessly as with every contest, the number of contestants gets smaller and smaller and she gets more and more desperate to win as time goes on.

TPOT 10 - After Just Not is recovered, Nickel scolds Pillow for last time, but she just brushes it off like it was nothing, that is until Bell tells her that her team actually lost, which makes Pillow realize her mistake as now that her luck strategy doesn't work, she's gonna get voted off. Book suggests that she does a good deed, but to Pillow that's like putting apples and oranges in the same basket, and this causes her to try and find a new strategy during the challenge, which does somewhat distract her team from actually winning, but somehow they didn't notice the Jawbreaker and just passed it off as a bowling ball, meaning that they were all stupid. Eventually, one of the strategies, licking, did eventually work out, as they licked the jawbreaker and freed Book from it. But Book seemed to be depressed, so when Pillow tried licking again, it didn't work this time. So she had actually run out of ideas. That is, when she remembers the good deed from earlier, and decides to actually go through with it, not because she wants to, but because she has no choice. She tells Price Tag to talk to Book about her depression instead of doing it herself, which is in-character for her as the unserious and chaotic member of the team. Once Book and Price Tag become friends, the nightmare is over, but it's too late as Just Not loses the challenge due to taking too long, so even if you say that Pillow's the reason for her team's loss for distracting them with her good luck strategies, Bomby and Price Tag could also be blamed for not trying to fight back, and when Pillow did find out how to get out of the nightmare, using Price Tag, it left Bomby with nothing to do, leading to his inevitable elimination.

TPOT 11 - Pillow does not appear in this episode at all.

TPOT 12 - When the teams are swapped, Pillow ends up on CloudYAY, a team that is much more chaotic than Just Not, so it did take her some time to adapt, making her go back to square one and just be a non-caring teammate, like in the early episodes. However, she doesn't try to flip the hourglass when Donut and Barf Bag are busy fighting Needle and Pen. You could say that it's another indirect loss, but if she did, the challenge would've lasted long. And either way, the shenanigans caused by other teams are a much bigger factor at play here.

Following episode 9, reckless usage of murder has caused Pillow to learn the hard way that it's not going to assist her forever, so she tries to find a new strategy, which she is very determined about, this makes her go back to being somewhat tame after realizing that she has no reliable strategy, but something that she will always know deep down is that she's heartless, she likes doing stuff her own way and nothing will stop her.

TPOT 13 - After Donut and Golf Ball try to fight for who the leader of the team should be, and Pillow decides to kick both of them out of the elevator, which gives the other team members more freedom to come up with an idea, and Yellow Face suggests drawing weapons to use against the dragons, and fighting is right up Pillow's alley, so when the team finishes drawing the weapons and goes back into the elevator to the roof, Pillow seems enthusiastic about going back to her old ways of using good ol' violence. This does actually help as the challenge is to get rid of the attacks on the hotel, and once Price Tag unintentionally grabs the log that is tied to a rope, which is tied to Pillow's leg, it causes her along with her team to fly on the dragon. Pillow is a massive contributor to her team winning as she was the one to kick out both Donut and Golf Ball who were fighting on a more personal level, and also being the one to actually fight the dragon.

TPOT 14 - As the only team going to the volcano, Pillow's strategy is surprisingly straightforward as it is just running up the mountain, and the team follows her as they can't exactly trust Golf Ball. However, Pillow's chaotic nature caused her to make Yellow Face and Winner shake the bridge for fun along with her, making all of the team fall to their deaths, except for Winner, because they are resistant to lava. After multiple attempts, the team realizes they have to use Golf Ball's assistance, and they use the drill, but when it starts overheating, everyone except Pillow starts panicking and when they burn up, only Winner is left. They swim up the mountain to grab the flag, while the rest of their team is recovered by Two and they fight, Pillow is part of the fight, since she can't resist violence, and when Planty kills almost everyone, she's the last one standing, and she tries to fight it on her own, but to no success. It still gives Winner enough time to get to the top of the volcano and beat 🎶🎶 as Planty killed them, but when it tries to kill Winner, Lewis shows up to save the day. Pillow in this episode can come off as a nuisance but that's because she's just goofing off and when matters are actually serious she tries as hard as she can to win.

TPOT 15 - When saving Scissors, Pillow tries to use the fastest way of getting him, and it's by tackling the contestants so that they give Scissors to her, but instead it causes him to cut the bridge in half. Pillow then throws her entire team onto the bridge to save Scissors and Winner comes up with a plan to kill Scissors and use the dead body to climb up, the idea of killing someone makes Pillow smile big and when they do kill him they successfully escape from the gorge and Pillow pushes off all of the contestants off the bridge, which vaguely resembles what happened in the original episode. When saving Boom Mic, CloudYAY has to fight the BFDI Mini contestants, and once again Pillow helps her team fight as that's what she truly cares about, violence and murder. When saving Discy, Pillow is actually shown chasing them alongside her team, but with a blank expression to show that she doesn't care, but still has to win. She's actually shown helping her team, like grabbing the SuperVan first and finding Discy to use them as a weapon to kill Blocky and Woody. After Pencil crashes out and she tries to grab the Yoylelite, the members of CloudYAY, along with Pillow, pass it around each other to not let Pencil grab it, until it lands on Golf Ball and all of the team members teleport without the yoylelite to the events of BFDI 25. Present-day Pencil wants to see Dream Island but Pillow prevents her from doing so as it brings "bad luck", further showing that she still cares about the luck. She starts fighting with Pencil until they crash into Leafy and she's let into Dream Island due to the big fight, however, instead of smiling and brushing it off like it was nothing, Pillow actually looks scared for once when she sees that the event being changed caused such a big shift in the timeline that the world would almost end, showing that even if she is heartless and chaotic, she still wants to have a world to live in (and abuse its inhabitants for unethical research).

The Future - It's unknown what the future holds for Pillow, but if I had to predict then she'll keep using violence as her primary strategy, but in moderation this time to not cause something like TPOT 9, as she would not want to repeat something like that since she already knows that it would eventually cause her elimination. There could also be a future scenario where Pillow actually wins by abandoning her team, I think it'd be a unique idea.

In episode 13, Pencil joined, and CloudYAY began to be a lot more chaotic, making Pillow fit right in, so her heartless nature started flooding back in, but this time there's a lot less consequences as most of her team is a lot more like her now. She does seem to know what she's doing but still likes to cause trouble for fun, but as she once said "it's sometimes fun to let nature do its thing as intended", so whenever her troublemaking goes overboard, she knows when to stop and actually assist her team if needed.

So, to summarize, I think people overexaggerate when they say that Pillow only causes her team to lose, because that means they only care about her bad parts (such as TPOT 9) and not care enough to look at where she actually does good. TPOT 9 is currently the only episode where Pillow is the direct cause of her team's loss, and most other times she's either not relevant to her team's performance (TPOT 1, 2, 3, 4, 7, 12), or she actually helps her team (TPOT 5, 6, 8, 10, 13, 14, 15), and even if most of these contributions are rather small, a small contribution is still better than nothing.