I'll bet car dealerships will be the first place in CA that you will start seeing college athletes on the billboards.
And it won't just be the top guys in the state. It will be the top guys on the local team. Even for smaller schools.
Then ask the 4- and 5-stars.
That is to say if $shoeco wants to sponsor $bigplayer but does not want to increase their overall athletics funding beyond its present $100M level, they will not take away $1M from $bigplayer's school, they'll take it away in very small amounts from all schools they sponsor.
That's laughable.
The best high school basketball players are only gonna be in college one or two years in any case. It's legal formality currently that makes them go there.
The idea that draft picks and their families are going to forego free money in California for the purposes of supporting the NCAA is, again, just a bit fanciful. These guys are gonna get drafted no matter where they go. So I can pretty much guarantee you that their agents will swing them to Cali.
The objective of the very best players is not to merely pay for college, but maximize their chance to join professional teams. Those odds are maximized by access to world class facilities, equipment, trainers, coaches, medical care, and more. Winning helps too.
If some schools have less money because sponsorships are going to specific players instead of the school/league, they will be able to provide fewer top-tier resources to players. Consequently, those schools will be less attractive in the areas of essential importance to the very best players.
If the very best athletes gravitate toward non-player-sponsorship schools, it will create a self-reinforcing cycle to get other top athletes, because they want the best teams to maximize their chances of winning.