Name, image, and likeness is a concept within the law of right of publicity. It’s a quasi-intellectual property right that we all have.
The argument goes that NCAA institutions were acting in concert (i.e., conspiring) to prevent students who are athletes from making monetary use of their own rights of publicity, since the standard grant in aid that provides athletic scholarships required those students and only those students not to be able to monetize their rights of publicity. Those contracts were not negotiable on an individual basis: you want your scholarship, you only get it on our terms. And the “our” was all the schools, the conferences, and the NCAA acting as one when they should be competing to provide better terms to get better athletes.
As such, those contracts - “contracts of adhesion”! - violated the antitrust laws. Other professional athletes can legally bargain away those individual rights of publicity through a collective bargaining agreement as permitted by the labor laws, but the NCAA wasn’t allowing that either. So now we’re violating that area too.
Untangle all of it - the lack of a CBA, the should-be-unenforceable contracts of adhesion, the antitrust violations, and the schools’ interest in not labeling these students as employees - and the way you can compensate athletes without creating unintentional issues with all of that is simply to allow them to earn compensation via an individual right that is untethered to their labor. That would be for those individuals whose name, image and likeness have commercial value - their rights of publicity.
Everybody wins! (So the argument goes.)