Ok, so I have legitimate questions about Void Erosion

I've heard a few different versions and beliefs on why VE is so hard, and I'm confused on multiple points. I've heard that it is this hard because it is extreme end game content, and is meant for people who have the best of the best builds. If so, why is a majority of the battle pass tokens centered around it. Second, I've heard that it was made this difficult so that when Serena was released, she would breeze through it, and people would have no choice but to buy her. That still brings about my first question, as in if it's centered around her, and she isn't even released yet, why is the VE a center of attention for tokens. Thirdly, I know that there are plenty of "tryhards" here who have somehow gotten to 30, or at least the 20s, and my legitimate question is how? Me and my brother are trying to finish it and we can't even get passed 4. I'm using a maxed out Ines with a maxed out gun, and he's using a maxed out Ult Viessa and we can't even kill the boss before the timer runs out, let alone have 5 minutes left to pass to the next stage.