I personally believe a players development comes mostly in the gym and weight room, grinding 6 days a week all year long.
you get to show your development in games, but you get better in practice.
a redshirt year isn't spent sitting on your ass. you grind. you get better just as much as you would have if active.
it's in a coach's best interest not to redshirt a kid. have him available. maybe he can help. you need to win games to keep your job.
but I believe it's in many kids' best interest to take the redshirt unless there's a clear path to major early playing time. get better. cash the check. have your 4 best years to maximize your college career, your chances to play after college, and your college NIL.
just my opinion.