Zidane is a very different person, I sometimes have difficulty understanding him. He is very successful but can do unpredictable things. That's why a team managed by him can either become champion or finish at the bottom of the league.
I wonder if he can be successful in a team like Manchester. If he signs such a deal, he will want to earn a lot of money, Manchester United is a difficult team

It's true, Zidane decision is very difficult to predict, especially regarding his future. There are many events that remind us all of the surprises he has done in the past, both as a player and as a manager. The growing rumors linking him with Manchester United could be true, and it could be that Zidane has rejected the offer previously. Maybe in the future The Red Devils top officials will try to contact him again, as a replacement for Ten Hag, who is currently almost failing to meet the team expectations.
Of course it is true, Zidane will demand many things from club officials to build the squad according to his wishes, especially the budget for spending on players in the transfer window. Apart from that, management must also be able to meet the salary that Zidane wants. If only the Glazer family were willing to relinquish ownership of the club to Sheikh Jassim, then they would not worry about the budget.
The rumors that have developed so far cannot be trusted because as has happened before, Zidane rejected the offer because his wife did not want to move to England. He has also turned down several other teams including PSG, but I think he would have a very hard time turning down Real Madrid's offer should they want to sign him once again next season.
Zidane was not brave enough to build a club that was in decline because he knew he would probably fail to revive its statistics. Zidane has won many titles with Real Madrid and has made himself one of the most successful coaches with the club, but of course he would be very worried if his reputation was damaged just because he failed to win titles for another team. I hope my assumption is not correct, but that's what I think is why Zidane hasn't wanted to coach any other club besides Real Madrid all this time.