Breece Hall is one of the best RBs in football. Very likely top 10. And yes, him not having a 1,000 yard season is 100% because he is on the Jets. 100%.
He is almost a mirror clone of Jonathan Taylor, and actually has every bit the ceiling. Coincidentally, both of these athletic freaks had one of the highest combine aggregate scores of all time - scoring in the 99th percentile. I believe as of a few years ago there are only six running backs in the last 25 years that have achieved a score like this. Unfortunately for Breece, the NFL is highly reliant on where you go, who is coaching you, who is the GM, what is the style of play, etc. Jets are just a loser organization.
The college you went to matters a lot too. Bruce was a better college running back then Bijan Robinson. Which is why the coaches voted Breece ahead of Robinson in the first team running back votes and offensive player of the year awards. Breece was also a better pass catcher in college. Yet, in the year after Breece's draft, Robinson goes in the top 10 and goes to Atlanta, where he is heralded as a stud freak. Breece is bigger, faster, and quicker than Robinson.
PS. David Montgomery is also a top 20 - 25 running back in the NFL.