A little while back I had taken a look at that Michigan championship team, they had 11 games that they won by 20+ points and only had 3 one score games. JJM only averaged 22.5 attempts per game, but when you factor in that almost every game was over by halftime, it's not bad. The passing game personnel around him wasn't great, 0 NFL WRs and the OL was much better at run blocking than pass pro and none of them are starting anywhere in the NFL. He did have 2 TEs who are both starting in the NFL, alongside Corum the workhorse.
His problems with not being ready for NFL speed leading to footwork/mechanical issues killing his accuracy which was not a problem in college outside of not having an accurate deep ball. Zero durability concerns in college, and the immaturity/mental issues weren't a thing either unless the Vikings missed that in their interviews with him that other teams did. He was also very good at not turning over the ball too.
I still think he's a 1st round caliber player in hindsight, maybe late 1st and certainly not on the tier of Williams-Maye-Daniels. Plenty of 1st round picks just naturally bust when they undergo the transition from college to the NFL, and it looks like JJM is headed that way.
If you don't think he's a 1st round prospect, then you also shouldn't think that a certain other prospect who was in a run-first offense that only threw the ball 23.6 times per game as his juggernaut team won the national title... his name is Fernando Mendoza and he's getting drafted #1 overall in a couple months. Obviously there are other differences between the two, but the point of my argument is if we're going to use passing volume in college to knock down QBs, then other good prospects are going to be downgraded for reasons out of their control.