Football

...to stick with college another year.
If they're 4th round talent, they're still a star on their college team.
They can make as much money in college as in the NFL on their first contract.
They get one more year to refine their skills & still get to be a kud one more year. That's definitely true of that change of pace RB at Notre Dame because he said so on national radio!
Not the 1st round guys, but lower rounds? There is now financial reasons to stay, even if it means leveraging the transfer portal to get another school to give them more money.