Evans isn't going to be ahead of him, and I think you're exaggerating how much better he is. He's not got better technical ability than Jones. Not that it really matters for a centre back and not that Jones is brilliant on the ball himself, but he's not better on the ball than him.
People are only really saying that Evans is a much better player than him based on the past few months. Yes, Evans has played well, while Jones hasn't, but I still expect Jones to comfortably be the better defender of the two in a couple of years, and I expect him to probably be light years ahead of Evans once he reaches his prime.
Evans is a good player who will continue to improve, but I don't see him being anymore than a good defender to be honest, even if some disagree. I feel that with Jones, on the other hand, he really has the potential to be a top class centre back when he's developed more and ironed out the mistakes in his game, which are largely down to inexperience in all fairness.
I just don't agree that Jones will become a new O'Shea for us. It's nothing against O'Shea, but he was largely a utility player because he couldn't really permanently nail down a spot in the team. Jones will probably be able to once he reaches his prime, and those who say he won't be able to are probably basing it on a few months of poor form, which is a bit kneejerk.