Position battles are tough, and they can have gut-wrenching impacts on the losers, especially when they're college kids. That's why the college football transfer portal has been so active recently.
It's easier than ever to head to another school, and it's getting more common for players to gain instant eligibility soon after. That's especially the case with quarterbacks since only one can play at a time.
The wear and tear of football necessitates multiple running backs to play. More than one receiver is normally on the field at the same time, and players at the other positions on both sides of the ball can transition to other spots more easily.