Without being clear, SCOTUS was quite clear on this. Individuals own their own NIL and can do with it as they wish. The only caveats that currently exist, like competing contracts with the school or unsavory business types, are on thin enough ice. I was never a proponent of NIL. It has wreaked havoc just as I said many times.
As soon as the NCAA, a conference or school tried to cap NIL, they would be sued in federal court and they would lose. No other student is capped in any way in using their NIL. The fact that few have any one buying isn't relevant.
As you see, no one seriously talks about trying to cap NIL. It would be the very definition of "arbitrary and capricious".