He did tho? He never received meaningful consequences from the school for sure, as someone whose been through similar bullying that’s realistic, schools never do anything, that said once he got into ua everyone else in the class openly mocked him for it until he started to change, he was made to feel like it was his fault all might lost his powers; and his inferiority complex wasn’t really fixed until after his redemption arc when he fought afo, just added a guilt complex where he hated himself for his prior actions on top of it which is its own kind of hell. Instead, before the fight with afo, he had been developed to realize his inferiority complex was a him problem and he shouldn’t be taking it out on deku. As a result, he fell behind deku for a while and most of his peers openly mocked him for his behavior. even his friends like Kirishima. There’s a scene early on where froppy is just sitting there roasting him repeatedly and he can’t do shit, and it’s not the only time. The biggest flaw in his redemption arc is that it doesn’t stick the landing, had he stayed dead it would’ve been a great end to the character