I used to think Manchester United signed wrong players in the past, and that is why Manchester United couldn't improve their performance, but after Manchester United sold some of the players who they thought weren't good enough to play for Manchester United to other clubs, those players performed well at their new club, and a player like Scott McTominay helped Napoli to win the Scudetto. That is when I knew Manchester United's poor performance was an internal problem, and Manchester United players aren't 100% responsible for Manchester United's poor performance. If Manchester United wants a total change at Manchester United, they should improve the things Cristiano Ronaldo pointed out were the problem why Manchester United is finding it difficult to challenge for the Premier League title.
I was hoping that you mention the things Ronaldo pointed out that can improve the team, well perhaps I missed that part in previous conversation.
One thing you should know is that, the process of rebuilding a team takes more than just selling out players and bringing new ones. It takes time to actually do it. But Manchester United is not a club that can give a coach all the time, they want instant actions. For instance you see the Mikel Arteta project, has been going on over two seasons before the team was able to be rebuild. Meaning as a coach you have 85% responsibility on the performance of the club after your debut season.
Coaching Manchester United, a big team with the most fans in the world, is not an easy job. Especially after Sir Alex left, which was initially a stable team but then fell apart, every coach who comes must get a lot of pressure from both fans and club management. How many times has Manchester United changed coaches but what happened was that there was no change because all parties expect every coach who coaches Manchester United to always perform well and not to perform badly, of course this is impossible. Because as you said, a coach in building a team needs full support from all parties, especially fans, and of course it takes a process like what Arteta did at Arsenal. Arteta came to Arsenal and didn't immediately get better, the same at Manchester United.
So I think Manchester United's mistake is always expecting instant results from every coach who comes. I hope Manchester United realizes that so they don't make the same mistake. They have to give Amorim time to build strength with his philosophy and make sure he gets full support. If they perform badly this season, it is very bad but we have to see him come to replace Ten Hag who is in bad condition. So Manchester United must give time and give full support to Amorim for at least 3 seasons because fixing Manchester United is not easy. This is not building a team but also having to build chemistry, also having to create a cool dressing room and of course internal problems that do not need to be exposed to the public.