James is a young player who hasn't had the grounding that Traore has had. Traore has had a head start on James all the way through their careers. He developed at La Masia, he joined the league in 2015, dropped down and had at least a season in the Championship before being in the PL for the last three seasons. And yet, despite that he's only just now started making his mark. James, on the other hand, has played half a season at Swansea and a failed loan at Shrewsbury. The step up to Utd has been massive. Much, much more massive than Traore's from Boro to Wolves.
Surely, it isn't beyond imagination that James progresses further the more time he spends with better quality players and coaching? This is his first season here, and due to issues with the squad and injuries, he's been played much, much more than anyone would have preferred. The only way is up for James, and if he wants to have an example to follow, then he can look at Traore. Especially considering his productivity isn't a million miles away from Traore's, and that too in his first season. I've seen quality Utd players and fan favourites have worse first seasons than James is having and progress further..
On your point re Sancho alternatives, I'd be more than happy if we didn't put all our eggs in the Sancho basket. The issue is, I just don't see Traore as being at the level required. If we didn't have James, I'd have been more than happy to have him as a squad player, but at the price we'd likely be paying, his productivity just isn't there.