If we wait until 2024, I think it will be a bit long because what Real Madrid wants is that at the start of the season, Mbappe is already at Real Madrid to be able to dominate the game this summer. but if indeed Mbappe is retained by PSG for me it will only be in vain because Mbappe's desire to win the UCL title has long been and maybe only by joining Madrid can he achieve what he wants.
So far there is still a chance to sign Mbappe. Madrid have that chance, they might just need to spend a lot of money to get him. The transfer market is still long, Anceloti could have many alternatives if he does not get him. Benzema is indeed no one who can replace. But now that he is gone, Anceloti must use the players he has to compete. So it doesn't matter there will be new periods and new problems when the best players leave.
I don’t understand why Real Madrid would want to spend that much money. I think that would be a stupid decision to make. Real Madrid can just get another good player for that type of money. If that player performs well Real Madrid will be known for making good transfers.
But if that does not work out Real Madrid can actually go for Mbappé the next season because then he will become a free agent. And at the same time, Real Madrid will have to perform really well in this next season. So probably Real Madrid will actually want to take that chance. But the price is going to be really heavy.
Regards
Duke