Defending the current state of San Francisco on the basis of not being as racially segregated on one measure as New York City sort of implies that it’s one or the other. If that’s not the implication, it’s irrelevant.

you really misread me. I'm not defending either city. They are both incredibly segregated, unjust and oppressive to the lower castes.

Is there evidence that supports this against the more likely causes, e.g., rich people just want to live around other rich people, people of any SES prefer to live around those who are culturally similar (and culture correlates with race in America), etc? In other words, I don’t think we have to resort to mustache-twirling caricatures to explain an increase in racial segregation.