For better or for worse (worse, in my opinion) Pep has always seen Jack as principally a winger. I don't personally think it's his most productive position, any more than I think it's Phil's. Jack can't go outside his man and beat him for pace — ever, apparently — which makes him predictable in that position. Especially for the full back. Both Doku and Savinho are more natural wingers, and since the first is 22, and the second is 21, where Jack is 29 — oh and Bobb's looming up on the horizon, and he's 21, and may turn out to be a more exciting winger than any of them — it's difficult to see how things are going to shift in Jack's favour. Jack's favourite gambit is to cut inside, across the pitch, keeping close control of the ball, it has to be recognised, maybe drawing a foul, or putting the ball over to the opposing wing. All quite useful, depending what stage the game is at. But that's not going to turn a game on its head with something that nobody has predicted.
Jack is too good a player to sit around warming a bench (or not even in the squad!) and deserves to go to a decent club, in or outside England. I think his days at City are numbered. At Villa he was a big fish in a rather small pond. Not so at City.