For Florentino Perez, the club is above all else and does not want Madrid's big name to be played by one player whose only intention is about salary. Therefore, Mbappe must be able to position himself and no matter how big he is now, with all the fame reported by the media, it cannot make Madrid have to beg and submit like PSG did. So in my opinion a club as big as PSG will lose confidence if they let Mbappe go. That is also the reason PSG insists on retaining Mbappe.
On the other hand, Madrid has the freedom to determine which striker they want to choose and give them a special place as the main striker. But what is certain is that this player has a vision that is in line with what Madrid wants to achieve. Achievements and trophies are just bonuses as long as they can provide mutual understanding to each other.
He is famous for bringing players that are super famous, and still making them part of the team. This dude managed to bring in all those ronaldo, ramos, modric, kroos, bale and so forth period, and even before that all those beckham, zidane, figo (big deal), carlos and so forth period as well. So, he knows that it is always great to bring in players that are world famous, whoever is the star of that period, he will spend one HUGE amount per year, and get the star of that period to make the team better.
I believe that if it was just about money, he would be easily spending 100 million and get Mbappe today, but he knows that it is not about the money, it is about the fact that the player, no matter how star level he has, should always be part of the team, and not build a team around the star. He won't let Mbappe have what he had at PSG, be the star that the team is built around, so that is why he may not like the prospect of getting him. Or maybe he does, we do not know yet.