There’s a simple reason football, and really most other sports, has grown into a year-round pursuit for many athletes.
The body is a machine that requires constant upkeep to operate at a peak level. The skills surely matter too, and there are arguments about honing them constantly or diversifying to avoid overuse.
But athletes can gain a lot from living well and treating their bodies correctly. It’s not always the easiest to get a young person, athlete or not, to do that. College football players fall into that category, and while teams can do a lot, with offseason-scheduled lifts and training tables to feed players, much falls on their shoulders.