I agree that the NBA should remove the age limit. The age limit wasn't put in place for the benefit of the NCAA, it was put in place to protect NBA teams from themselves by giving them an extra year of information about players before they can be drafted. But if teams want to gamble on 18-year-olds, they need to get systems in place to evaluate them better than they were last time we had prep-to-pros.
The college system has a ton of flaws. The money being made off top football and men's basketball players is obviously an issue. However, the NCAA is not JUST about the marketability of the players. College basketball is better for the fact that Zion is playing but it's not like no one watched because Lebron and Kobe didn't go to college. Duke, Kentucky, Kansas, Carolina, UCLA, plenty of schools have fan bases and funding that care more about their team than they do about the sport. We're not talking about basketball fans in those situations, we're talking about fans of the school.
So what percentage of the athletes are being exploited? And how much of it is the fault of the NCAA versus the NBA? MLB has a proper farm system available to kids but plenty still play college baseball. If the NBA put the money into the G-league, that would actually undermine the talent pool in college basketball because it wouldn't just be the lottery picks who might skip college, most pro prospects could go that route if they choose to. The NCAA is just filling a gap created by the NBA's laziness, in that sense. The money made from football and men's basketball funds every other NCAA sport. It creates opportunities for thousands of kids.
The part that's really screwed up is that the NCAA doesn't lack for options to make it fairer on kids like Zion without having to pay players in general. Allow kids to sign shoe contracts. Allow them to sell their likenesses. If the local pizza joint wants to pay them to film an ad, why can't they make a few hundred or few thousand bucks depending on their value? That's an easy fix that they don't want to allow because they can sell Duke #1 jerseys for $130 without having to give Zion a cut.