It's easier to see the 5 stars that went bust than the ones who were as advertised, I think. Plenty of them, RBs too, had excellent college and pro careers.
I still think a very good RB can do very very very well behind a great OL and scheme, versus a great RB behind a so-so OL (and scheme).
A run oriented scheme can find itself ahead by say 14 points in the 3rd quarter and just run clock and build up yardage, wear down the defense, and make a back look good in the paper.