"off these athletes"
No. The value is 99% in the brand of these institutions built up over a century. The value is in alumni bases who would attend and watch even if there was an across the board talent decrease due to more players going pro. 99.99999% of athletes are worth less than the amount they have been being compensated when you add up the value of their scholarships, stipends, training, tutoring, etc. There's a reason that these schools were already compensating well more than the lower rungs of pro leagues (the best indicator of their true market value), and why athletes chose to go to school rather than jump to professional options elsewhere. But all for the benefit of that .00001% that have a pro future ahead of them, the entire college sports model is getting ruined.