Quick question for the community: what's the knock on Marcus Mariota?

This isn't to advocate for trading Russ or anything like that. I'm just asking to better understand the quarterback market right now, considering the possiblity of a Wilson trade.

So Mariota was a super highly rated prospect, #2 overall. He had, by QB Rating, 2 solid seasons followed by a dud, followed by 2 more solid seasons. By AV, he had an okay season, 2 rather good seasons (like Russell Wilson good), then another okay season followed by a season in which he didn't get volume because he lost the job. By QBR, he had an okay year, 2 years on the level of '16 and '17 Russell Wilson vintage, then another okay year before losing the job. By narrative, it sounds like he lost the starting job after a couple real donkeys in the 2019 season. Russell had had stretches that bad, but he had earned the benefit of the doubt whereas Mariota had not despite showing real potential and generating solid results.

So Mariota was never quite the passer Wilson is, but he seemed to me to be a solid performer at a tier below. He's in every way better than Geno, for instance. He has all the physical skills you could want, again not quite the arm strength of Wilson but above average and easily peak Russ's equal with regards to wheels. His main weaknesses seen to be similar to Russ, in that he reacts to pressure that isn't there and walks into sacks. His main strength also seems to be similar to Russ's, as he's a very dynamic QB on the move with both his arm and legs. He also seems to have that winner's special sauce, racking up plenty of 4th quarter comebacks and game winning drives (leading the league in both in 2017).

Again, not to advocate anything about picking him up and/or trading Russell, just curious as to why Mariota is a nobody these days. He seems as much worth taking a chance on as anyone in the draft. Yet someone like Russell is by trade value and salary worth many times what Mariota is, or ever was. Why is that? What's the knock on him that I'm not seeing?