Question on moving players between offense and defense

This does not seem to happen very much anymore. Is this because players are groomed and developed at such a young age, and go to position-specific camps, that they come in and tend to stay at that position, or move to a proximate position (i.e. come in as CB and become safety, or OT becomes OG or C)? Or maybe it happens a lot and I don't know it.

Reason I ask is (a) it seems like it doesn't happen as often (b) I was struck by how well Xavier Watts played - or at least seemed to play - more active than some of the other safeties. I also saw Sainristil play great as a DB for Michigan in the UM-OSU game, and he was a WR for three years and moved his senior year.

I suppose such moves typically happen very early on (i.e. right when arrive in 1st year). It doesn't seem to happen much at all after 1st year - and then only with injuries leading to a big need. But Ara and Lou certainly did it more after year 1, depending on how they viewed someone.

One wonders if there is any talent on the existing roster that can help in different places where we have holes.

Maybe the world has changed and this is not the same option. But I did like the Watts move and hope he plays more next year.