I think folks tend to over-estimate the degree to which these NIL court decisions will affect the viability of the NCAA.
It is a big organization that does a huge amount of stuff.
Setting aside recruitment and eligibility enforcement actions, only some of which have anything to do with NIL, there are:
(a) A host of other rules in the NCAA college sports rule books. One big massive book for each sport, in some cases, more than one book for each sport because Division II might have somewhat different rules than Division 1 and Division 3, etc. All of those rule books need to be maintained by the NCAA. They all need to be updated from time to time by committees of representatives of the schools and conferences, hosted by the NCAA. They also need to be enforced; the on-field rules are enforced by the conferences (they hire their own referees) but the off-field rules are enforced by the NCAA.
(b) Championship tournaments to run, for all but FBS, in dozens of sports at several divisional levels. March Madness, of course, but also the soccer, track and field, swimming, volleyball, etc., etc., etc. At each divisional level. Lots of tournaments, year-round. The NCAA plans, coordinates, hosts, mans, and cleans up after all of those.
As those two examples show, the NCAA does a lot of things. Only one small part of which is enforcing the recruiting rules of Division I money sports.
Someone has to do all those things. If the NCAA were to go away (but why would they, given all these jobs?), we'd have to create a new NCAA just to do it all.
In short, the NCAA isn't going anywhere. They're only out of the business of enforcing the NIL element of recruitment.
Go Vols!