A pro hero uncle kudo would have fixed himðŸ˜
In a serious note, I think one factor that had a big impact on Katsuki's development in the beginning, was the fact that he went to UA and meet lots of ppl who were equal or stronger than him (both teachers and students) . This humbled him because before that he never were in a place like that so he thought he's the god of the universe. I wonder what would happen if he had a strong pro hero uncle from the start that he looked up to.
His dad didn't do anything about his behavior because he thought it's a phase and it's gonna pass while his mom thought violence is the answer. None of them obviously worked. I think a strong person like the uncle I described could have helped him improve his view exactly like how him, shoto, inasa, and camie did with those kids later when they told them let's fight and were acting impressed by their quirks (the pictures) . Which would be really good for Katsuki since you can see in the first Pic (above) he is challenging his dad and wants to see who is stronger, his dad or himself.
