Arsenal may not win the league. But they provide lessons to other teams about trusting the process. If Man U sticks with ten hag for 2-3 more years, they'll start challenging the title. Stability is key.
Facts. It takes time to rebuild and install a new system. I think Man Utd are now better placed to start competing at the top level. The problem is that most modern fans are too impatient and still believe that throwing mad money is the solution. Look at Chelsea as a prime example.
Manager powers are diminished unlike the past where now players are big brands and influential. However, a manger has to be ruthless to instill his influence. Arteta had to get rid of the skrrrr swag boys in Auba, Laca, Özil etc and though it hurt then, he had another vision. Ten Hag was also criticised for axing Ronaldo but he knew that the system he had in mind was mostly in developing new players with a hunger. Sancho is now at BVB because he and the manager couldn't agree on basic discipline.
It takes time but it is worth it eventually.