I think it's too early for us to say if Amorim has a worse performance than other coaches, because as we know if he coaches only half a season and the squad he has is also the legacy of Ten Hag, so we can't say if he completely failed at Manchester United, the transfer market next season in my opinion will be the proof for Amorim in building his squad absolutely, so we can see how the performance that Manchester United shows next season and that's when we can say whether Amorim is the right coach or not for Manchester United later.
But, if we compare Amorim with another coach who successfully managed the team in half a season, Amorim looks like he failed to manage MU based what on he did before. If we talk about players who can't compact on his strategy, Amorim should quickly adaption to the current squad. he was expected by many people to lift MU position from the bottom rank, but he can't do that so far so make many people are disappointed in his performance, and perhaps recruit a new coach to replace him. If he can't recruit a new player to fill up the gap position, I think he will not be long, and will be replaced soon by a coach who is targeted such as Xavi Hernandez.Amorim is a good coach, we can see his pattern of football when this current players are in form and stick to his instructions , which means that if the board, I mean Ineos try to support him with enough money to sign good player that would suit this structure, he'll do better than this next season, bringing in a new coach would disorganise the team once again, except they're willing to flush out many players and sign in fresh one's for the new coach, but since they're broke I think that's impossible.