Lamar's case seems predicated on health. Vick managed to stay relatively healthy but he also wasn't running at this frequency and he was a much more stoutly built guy. Vick was built more like a running back. I think, for Lamar to stick in that upper group, he just has to improve as a passer. All of his passing metrics are incredibly underwhelming.
36% of his passing yards on the season and 64% of his passing TD's came in their first two games, against Arizona and Miami. Both are horrendous defensively (bottom 3 in the league in defensive DVOA).
In the 5 games since playing those two awful teams, he has 4 passing TD's, 5 INT's, 1054 passing yards (210 per game) on 60% completion. Those are pedestrian numbers. 2 of those 5 games he threw for less than 200 yards and it honestly should have been 3. He eclipsed the 200 yard mark against the Browns on that meaningless screen pass that someone missed a tackle on.
He's fun to watch....but it seems unlikely that he would reach (to me), the ceiling of Mahomes, Watson, Wentz or Mayfield. He's more effective than Baker currently but long term, his passing strides need to be real for him to have long term success......unless he's just incredibly lucky and stays healthy for his career. It's just tough to believe that a QB carrying 180+ times a year is sustainable in any way....I also think he, kind of under the radar, is also taking a lot of hits in the pocket. He's been sacked 17 times already. My takeaway from the last stretch of games is that he has yet to prove he can play from behind and leverage his throwing to bring a team back with any sort of consistency. If he can play from ahead, his legs are an effective way to chew clock.