It’s an interesting idea, but if you were a truly elite prospect, would you want to share the ball with 11 other elite prospects, or be showcased as the #1 / #1A option in the NCAA?
I think the college super teams like Kentucky and Duke have proven that kids can go to teams where they are not 1,2 of 3rd options and still get drafted high.
If your an elite prospect you take the academy approach because you will
A. be getting a salary
B. be able to get money in form of a loan from agent or endorsements
C. be extremely exposed to NBA GMS and scouts
D. ideally getting better on and off court development then you would in college or over seas