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).

Your reasoning was fine until you jumped to your "doomed forever" conclusion. Clearly nothing is doomed forever if things like killing and racism are reducing.

Your theory explains why people misunderstand each other and are "doomed" to states of conflict due to how their minds work. It needs to go further to explain how good outcomes are produced despite conflict and misunderstanding.

Why do they accept "simple and blunt rules"? Where are these rules coming from? Why aren't the rules pushing people in the opposite direction? Are there other mechanisms beyond imposing simple and blunt rules on everyone? etc etc etc Don't be satisfied with your theory. It's a good start but keep digging.