I completely agree with you, Manchester United has been paying shit ton of money in players that didn't worth that much and I also agree with you that different players play differently in different clubs but isn't it strange that everyone plays bad in Manchester United but they shine or play significantly better in other clubs? Or players were playing very well but once they moved in Manchester United, they went downhill. This is what I don't understand about Man Utd, why does this happen, I understand that maybe politics is bad in the club but why do players don't play well there, why do coaches fail too, are they cursed or what?
Winning titles like Europa League is good, it's undeniable but they won it with Jose Mourinho already and years after that they have still failed in developments. They are now in worse position than what they were with Jose Mourinho in a season with Europa League title.
Amorim will be remembered by the club history and Europa League history if he wins the title with Manchester United this season, though after that he still has many things to do for developing the squad. One Europa League title from a crisis season in Premier League won't help Manchester United good enough for competiting Premier League title or top four next season. Anyway winning this title will give them more money, make their club more attractive with star players and hopefully if they can buy good players with a better development strategy, they will become stronger next season.