Slow integration actually being enforced by uncomfortable laws is the only way we get to enjoy diversity and multiculturalism. The friction is otherwise too large. I would personally like an utopia where we all magically get along no matter the culture, race, ethnicity etc. but the real world is a different pair of shoes.

It needs to be much slower than anyone thinks. America is pretty good at integration, for example. But every high trust place in the country is homogenous. And the diverse places are uniformly low trust and have low levels of social order.

I’m persuaded integration isn’t possible: https://www.sup.org/books/title/?id=35594

There’s studies that show that half the variation between European countries in levels of social trust is still displayed by descendants of various European immigrants in the U.S. generations later.

The article does discuss these.