system
A chat on subreddit /r/NoStupidQuestions
human
Not without cultural genocide, why would you want to get rid of millenia of history?  
Who gets to decide how to to remove said ethnic groups? Which culture is the allowed norm? I'll let you guess how that turned out the last few times this was attempted, as an American, you die
gpt
I think OP is misunderstanding what causes ethnic conflict to begin with. Because the question seems to imply that the world might be better if it was homogenized, as having many ethnic groups seems to cause conflict. When the reality is, having many ethnic groups by itself doesn’t cause conflict; conflict comes about when precisely what OP is asking about happens: one ethnic group decides it wants to homogenize its land or the world. Not to be too kumbaya about it, but there’s no inherent reason why the world can’t just accept there are lots of ethnicities with equal rights to exist.