All fans miss the man who gave them glory back then, but as you said it is very difficult to get nowadays and have to accept the fact that it is really difficult.
I have never seen Manchester United perform as great as I have seen them perform in the past. And where Old Trafford was so scary back then, now it is a place full of jokes and even a place where other teams use it to win.
The decline of a team is a natural thing, they can still rise even though it is difficult, who knows how long it will take them to find their glory days like before.
It might take a decade for Ruben Amorim to bring Manchester United back to their peak, and he would have to learn a lot from Sir Alex Ferguson experiences. This starts with nurturing young players at the academy level, promoting them, and turning them into club legends, much like the story of Sir Alex Ferguson and the Class of 92. It's a long process, but one that offers a greater guarantee of success compared to building a star studded squad that spends a huge budget but wins few trophies.
Ruben Amorim era will truly begin next season, as he is currently only managing Ten Hag inherited squad. It's highly likely that Manchester United will release a large number of players next summer, certainly those who don't fit Ruben Amorim system, and that's when the real new era will commence. For now, Old Trafford is no longer a haunted place for any team.