By the way, Manchester United has really talented players like Garnacho, Mainoo, Amad Diallo and more. One of their focuses should be the development of these players.
All of these players have a big potential to tell the truth. They shouldn't be wasted. They will be the future of this team. I like this side of this team as well. I always see really skilled young lads waiting for their turn to show their skills. They never fail too. Especially Garnacho - Mainoo are doing great recently.

Big teams would be after them shortly.
Would you ever want these players to be sold at this young age?

My answer will be, never!
They do have great players with massive talent but are they being trained at a proper level to actually increase their stats ? I would say no and it's not because of whoever is the coach , it's because their facilities are getting way to old to actually give their players proper trainings. We can remember that CR7 was shocked when he came back to United to see the same old training facilities for over 15 years without improving in any area so no doubt United is where it is today.
I hope they won't sell those key players because they represent the future of United to make this club great again but until they won't improve outside the stadium , I doubt important things will actually happen with United.