I want to see Man United's decline from the other side. Man United has changed coaches several times starting from Moyes, LVG, Mourinho, and Ole has tried to coach Man United since SAF left, and now ETH. the results are also not good.
This means that the problem is not with the coach but with the players being burdened by the club's big name. fans demand players to perform optimally in every game, especially the demand to keep winning in every game. When negative results are obtained, especially against mid-table or lower-class teams, the players' mental pressure becomes even heavier because of their team's big name.
In my opinion, Man United needs players who have leadership like Ferdinand, Scholes or Vidic who are able to lift the team's mentality. Because so far Man United has not found a team captain who has a strong mentality.
If something needs to be replaced, then I suggest Manchester United change the owner rather than changing many coaches and players. The current owner would have to sell the club to a new owner who has the desire to build the club even better, which seems like a good thing to think about.
Manchester United will never be able to compete with Manchester City if Glazer and his family are still leading the club. I'm sure that's true because so far I don't see Manchester United being truly competitive under his ownership. Changing coaches will not solve the problem, but will only bring new colors and new drama.