To take it slightly further afield, it's partially why the arguments that diversity is the death knell of Western civilization or any other similar epithet is so misguided. These institutions shape our society and are shaped by our society and they only reward those who best fit the pre-existing mold. Even if we went whole hog on open borders or something else extreme, it would change very little since promotion to the role of decision maker would remain in the hands of those compatible with the existing system. It's no surprise that for all the talk about society, diversity, etc. and so forth, we still mostly elect vets, lawyers, and business people to public office, people who have shown a willingness and an ability to embrace and personify the existing systems. And that's never going to change.