Basically near the end of the first war arc, every chapter is reliant on epic cliffhangers that are hype bait (i.e. previous characters making reappearances or fakeout plot twists), the author is speedrunning the series to the ending and failing at it because he wants to include every possible plot point he can (i.e. UA traitor and Mutant racism to name a few).
The worst part is replacing an actually good top tier villain with their mentor who was a saturday morning cartoon villain that Horikoshi basically makes them a bootleg Aizen by having ridiculous backup plans that make no sense. Not to mention doing that as a clearly telegraphed ploy to rip off Vader's redemption arc from Star Wars.
Then there's how rushed everything is because the series never bothered to take any downtime after the war arc and immediately blitzed to the final arc which didn't have much build up.
Also there's so many expendable characters that Horikoshi pretends are important like a D-List hero who appeared in like 20 chapters getting the big hero moment in saving someone's life who they didn't know and should've reasonably died. Having a bunch of Izuku's classmates act like they are meaningful characters when some of them could be cut out of the story or killed off and it wouldn't leave much of an impact (i.e. Sugar guy, Tail Man, Tape Man, and grape rapist to name a few). I am all for an ensemble cast since some of my favorite series have ensemble casts but MHA has so many nothing characters.
The anime is basically in the beginning of this shit mountain.
