I would also make a slightly broader point. When highly drafted players fail in the NFL, it is usually not because they don't have the physical talent.
The NFL and its whole infrastructure of scouting and assessment is pretty good at figuring out which players have the requisite physical talent.
The problem is usually either:
a) mental, ie the player is not committed, or lazy, or selfish, or even plain dumb or whatever.... or
b) bad coaching - square pegs are put in round holes, players are not taught or managed well
What happens when players fail is that pundits and commentators say he was a bust, and he was always destined to fail. The reality is that how a player is coached and the system they play in is huge.
For example, Jared Goff looked terrible under Jeff Fisher. If Fisher had not been fired and had remained as the Rams coach for several more years I am reasonably sure Goff would be considered a bust. He just needed the right system and good coaching.
With Jones, I don't think it's physical. It may well be mental. He may well not be suited for the NFL. Some players just don't have the requisite desire, determination and discipline. But it may also have been bad coaching or the wrong system last year.
I think the jury is still out. But this year he has great coaching and has no excuse, so we'll know soon enough.