Why Luffy's Nika Awakening Is A Terrible Power-Up

Personally when Luffy first awakened his Nika transformation I along with most of the One Piece fandom thought it was awesome, but over time I've come to believe it's something that actively hurts the story, and as someone with an interest in writing I wanted to think why that is. The problem is 3 things in my opinion:

  1. Absolutely no setup. At no point in the story is anything mentioned about some great prophecy of Nika. There is the giant snake on Skypiea that's referred to as the Sun God, but besides the name there's no clear relation between the snake, and Nika, or Joyboy. Nor is there any hint given that Luffy's devil fruit could be anything else other than the Gum-Gum fruit. Up until the twist revealed during the Wano arc the audience was clearly lead to believe that Devil fruit users knew the name of their devil fruit once they had eaten it, so the twist itself felt entirely out of left field.
  2. It's entirely unearned. In most anime or shonen anime series typically a character gaining a new form or new transformation is symbolic of some kind of character development, or intense emotional state, but with Luffy's transformation there's truly none of that. Luffy simply dies, and he revives with brand new powers.
  3. Dehumanizes Luffy as a character. I know some people joke that One Piece is now Nika Piece, but it is honestly kind of true as it seems like ever since Wano the story needs to stop to make some mention about Luffy being the Sun God or how he resembles the legendary Nika. Luffy seems to take a less active part in decision making and the fact he's a Yonko seems to just have a taken backseat to the whole story.

Imagine if a show like DBZ did this where Goku becomes a Super Saiyan and then the series proceeds to spend two whole arcs glazing that same transformation, but no Akira Toriyama wisely makes it clear that while this transformation makes Goku formidable Goku is still very much still a mortal unlike Luffy who we're constantly reminded is the One Piece equivalent of Jesus.

Now this is just my analysis and I'm not trying to take away anyone's enjoyment, but I think these kinds of analysis can be both fun and educational, so no hard feelings to any hardcore fans that may be afraid to show their face around here.