The level between college and the pros (in pretty much every sport) is massive. Being able to succeed with limited body construction against other people with similar limitations is a good sign, but professional sports are grown ass men, many of whom spend 5, 6 figures on assistance optimizing their bodies, and playing a much more advanced game with much less room for error.

Draft picks inherently have to be projections of a pretty serious amount of future development just to be playable at all. You basically need a guy to double his capability or whatever to be relevant.