Strongly disagree that the running back position doesn't require above average talent. We have a great quarterback who's going to do most of the field position work. But a good power runner is still a very valuable thing because it forces the defense not to focus exclusively on pass coverage.
And LeGarritte Blount was not bad or mediocre for us. He had less than stellar YPC partly because of his role. He simply wasn't asked to run for field position that often, a lot of his runs were on the goal line and a lot more were short yardage by design and that is going to drag down a running back's YPC. And he still got over 1000 yards for this team despite Brady being there for most of the year, which tells me that Blount was doing something right.
People are relying far too much on YPC to judge between Blount and a guy like Gillislee, when the Bills simply use the RB for field position far, far, FAR more often than the Patriots do. Blount never had a chance to get large yardage gains because Brady was the primary yardage horse, not the run game. If they needed to make a big play most of the time the ball went to Brady, not Blount. When the ball went to Blount was frequently when a power run would be most effective, which was in short yardage and goal line. So of course his YPC doesn't look great. So while YPC is usually a pretty good barometer of running back performance, if you rely on it exclusively and ignore role, you're going to underestimate LeGarritte Blount.