These are the numbers at United. To be fair, it would be fair to compare the numbers at United and outside United. For example, Anthony has improved in numbers and overall since leaving United. Can you name anyone who came to United in the post-Ferguson era and has improved? There were probably some, but basically United is a graveyard of talent, I think that Garnacho really should leave and maybe he will progress in another club, he has potential.
Even if I will agree with you that Manchester United can be regarded as graveyard of players, it is so cool to understand that there are some strong and exceptional players who can still fit into the current situation of Manchester United. Player like Bruno Fernandes has been flourishing despite the continued poor performance of Manchester United.
This could also mean that Manchester United doesn't need upcoming players like Garnacho. They need proven players like;
Osimhen,
Salah,
Vini Junior,
Mbappé,
Lewandowski,
These players cannot flop in any club.
I also believe Manchester United kills the career of players. The Sir Alex Ferguson era was great but ever since he retired the club has not been the same. Not even Ronaldo could save them and CR7 is no flop. Some teams are just beyond redemption. If Ronaldo couldn’t help, what makes you think Mbappe, Vini, or Lewandowski will be able to change anything.