I'd say Manchester United hasn't changed, they only have few good players like Amad, Mainoo, and Mazraoui, other than that, they're the same.
I don't think Manchester United's performance was bad against Manchester City. Manchester United players were able to perform quite well against a strong opponent. Honestly, none of us thought that Manchester United would be able to win this match. Everyone considered Manchester City as the favorite. But in the end, Manchester United was able to win.
Manchester United was lucky in this match, there is no doubt about it. If Manchester United was not lucky, it would not have been possible to win this match. Manchester United was able to draw the match by scoring their first goal in the 88th minute. And by scoring another goal in just 2 minutes, Manchester United won the match. Manchester United's attack played quite well. But even then, I think Manchester United needs a more experienced striker.