I've said it before, the discussion around Pogba reminds me of Ozil's case. Both regarded as world-class until they went to relatively poor teams, and despite still doing the same things, their reputations fell through the floor.
I think for creators like Pogba and Ozil, they are very dependent on their teammates to look good. Also, due to their continental playstyle, they tend to not be as good as others defensively, which in England usually gets you a ton of stick. In that sense, it might be best if he left England for a league where it's not required to always look busy defensively, and where guile is more valued. He'll probably be appreciated more there.
If he is to leave, we can definitely replace his work on the pitch but it will require a lot of good moves from the management because right now, his productivity is covering up a lot of our flaws, even if his playstyle does cause some problems.