While this is true, lots of these kids love playing the sports they are on scholarship for. And many more would play with no scholarship - like the walk ones do. So "performing a service" is a bit of a stretch. They are getting paid handsomely - even without NIL - to play a game they love. Not a bad gig.That's not what the word "free" means.
If you have to perform a service in exchange for something, that thing you get in exchange isn't "free". You did work to earn it.