I would say that racial/ethnic homogeneity is almost completely illusory, because there's still diversity within the same race/ethnicity. People have diverse views and opinions, and that's only natural.

I think that dividing different races and ethnicity into compartments isn't the answer, because that will only intensify the polarization in the long term. Only through dialogue and mingling that you can eliminate discrimination, because discrimination is based on ignorance. People discriminate against another when they think "those people are so different from me", when they aren't actually that much different.

You might say "that naturally happens anyway", but then so do people "naturally" eat bad food, but that doesn't mean that we should advice them towards eating healthier foods.