people will say bakugou didn't bully izuku for 10 years because horikoshi never showed him bullying izuku every single day... hori didn't show endeavor abusing rei and shouto every single day either but we know he tormented them for years. read inbetween the lines y'all !!!

the first time we see bakugou he is 4 years old and bullying izuku. the very next time we see him (present time) he is now 14 and still bullying izuku. the timeskip is purposeful to show bakugo hasn't changed since then! izuku says so himself many times.

bakugou started bullying him during kindergarten and being the leader, other kids followed. acknowledge the past to learn from it. this is why he's getting development to begin with !!
anyways i enjoy their relationship and want to see them continue growing stronger together

bakugou did not go through hundreds of chapters of development for y'all to disrespect him by saying he wasn't a shitty person and had nothing to grow from

btw this isn't to say their relationship is 100% fixed now, 10 years is a LONG time. as horikoshi said, what bakugou did is unforgivable and he still needs to apologize. healing isn't instant, it takes time. i'm excited to see where their relationship goes !