I found this to be the norm in EU/Singapore so unfortunately it would be very hard to find a company that does not work like that.
I have been living in Asia for a while, indeed diversity is not seen as anything useful. It's not considered a criteria to be taken into consideration.
I have worked in diverse team and I have worked in a monoethnic team. I haven't seen any difference whatsoever in term of performance.
From my own experience I like working in a monoethnic team. And I like working within a team with a little bit of diversity. But when diversity is going too the roof, then my degree of joy at work start declining.
Being in a team where people are black or have vaginas is devoid of any value to me. And I tend to leave any companies that seek to optimize these criteria because I find the idea of hiring based on gender, sexual organs or racial consideration to be intellectually insulting.