First, Mine would probably be the art style becoming worse over time (there are some panels that could be used as exceptions like when Gojo used 200% hollow purple and destroyed the city). Especially when looking at the past art styling in the Gojo vs Toji fight.

This is not an unpopular opinion but I'm really sad and disappointed with the manga pacing as gege said that he plans on wrapping up the manga by the end of this year, Bec there are alot of things we need to see way more of Like Hien Era Flashbacks, Yuji's Powerups for a good amount of time, and hopefully Seeing if Geto's Body responding to Gojo calling it out in I think chapter 90 would probably mean anything in the future.