The NFL requires him to go to college for at least a year instead of maintaining a farm system like MLB and the NHL. Big difference. I have a relative in MLB's farm system and he already has some good money in the bank.
In medieval times they had something called an apprentice system. Young adults would accept a pittance for the benefit of learning a trade from the master. This is not the same as indentured servitude.
Apprentice mercantilism is not a bad idea even in these times. An athlete is getting more than just compensation or free tuition. He is gaining invaluable learning from coaches and trainers so he can become Pro material.
I have more compassion or concern for the trainer and water bucket boy enabling the “Star Player” than the athletes in question.