It may be worth mentioning that one of the, if not the, most powerful IP lawyers in the Bay Area is “only” a University of Iowa Law School grad.
https://www.quinnemanuel.com/attorneys/verhoeven-charles-k/#...
I suspect you're correct, though, that if Harvard closes those doors, talented people will go to the University of Iowa (my wife's alma mater) and do fine.
It is that we know that going to places like Harvard, you are much, much more likely to have a well-paying job, comparatively. Bonus points if you are rich and can do things more often with your peers. I'm not under the impression that the education is that much better (it might be, I can't assess that). The networking you definitely seems better. You are getting a foot in the door, a thing that poor families can't always get without a good dose of luck.
(The trouble, of course, is with career paths in which networking and prestige matter a lot more.)