I think an interesting / illustrative case is the AMA as the credentialing authority for medical schools. An association of people in the profession, who have a clear interest in the supply of doctors being low, has a clear lever by which to restrain the future supply of doctors. Independent of which specific people get in and how, for the country overall, most of us would probably be better off if more people got into med school, if there were more med schools, and there were just more doctors working a decade from now. The important question isn't just who should get the seat, but which policy choice gives us a better health care system.
I'm guessing the same is true for other areas, but it's just less clear. Rather than asking "who gets to go to the best schools", more interesting is "what policies at the best schools give us a country we want to live in a generation from now?" or "what choice yields the greatest benefit, not just to the student, but to society?"
And if schools don't want to make choices from that perspective, if they want to operate like luxury brands whose goods are valued mostly because they're rare ... then maybe they shouldn't get tax exemptions around their endowments, or public funds, or the respect and esteem of a population that thinks they serve some higher, refined purpose.