Garnacho had issues with Amorim, which prevented him from being given space in the team. While Amorim still trusted him last season, this season he has completely lost his place in the squad. He does have good ability, but his ego is high, and the incompatibility with Amorim has cost him his place at Manchester United. Not many clubs are interested in his services because Manchester United's asking price is too high. Napoli also expressed interest in Garnacho, but there was no follow-up, and now it seems Chelsea will also be unsuccessful in securing him.
Garnacho career at Manchester United seems to be stuck because of conflict with his coach Amorim. His reported high ego and poor relationship with manager have directly caused him to lose his spot on team despite his talent. On top of that even though clubs like Napoli and Chelsea are interested Manchester United high price tag is preventing transfer leaving Garnacho in tough spot as his club price for him is too high for other teams to pay.
Yes, the price of his tag is quite high for many European teams and they cannot afford to buy him, perhaps with a loan with right of redemption they could send him to other teams or they could simply change coach
Manchester united since Sir Alex Ferguson's retirement seems to have put a curse on this team. No other coach has been up to the task