I don't see your point. People still hate each other due to trivialities, we just mostly stopped killing each other.

If you wonder how we solved racism, we did it with simple and blunt rules everyone can follow such as "don¨t say the n-word" or "don't say that whites are better than blacks". People are still racist, but simple rules like that makes it harder to rile up a mob enough to burn down a black neighborhood (I know it happened in Tulsa, that is why I used it as an example since it probably wouldn't happen today).