I believe PSG has carefully prepared for Mbappé to leave. Last season, they were ready to sell him. A big team like them won't depend on him. They are prepared to push him to the bench or sell him quickly. PSG is a financially strong team, and recruiting many stars to replace Mbappé is easy.
Saudi Arabia's "money" would make Mbappé the highest-paid player, but he doesn't need this. 'Success,' as you said, Mbappé requires individual and collective titles. A talent like him gradually fades away with PSG.
I'm sure of this too. It’s hard not to notice that, given the presence of such players as Kolo Muani, Ramouche and Dembele in the team besides Mbappe, there is some “crowding” among the forwards. Apparently PSG hoped until the very end that Real would make an offer that would suit PSG and Mbappe would go to Real this summer, but Real have been strictly rational for many years and they decided to get Mbappe for free, even a year later.
PSG should not be dependent on Mbappe. And PSG management wants a stable squad. And that's why they coached Luis Enrique. Luis Enrique has experience working with new squads. I would say Spain's team is stronger because of Luis Enrique's hard work. And I believe Enrique will do well with PSG as well. First he is trying to stabilize the team. He is looking for a suitable match strategy for PSg. And if he is able to stabilize the team, I think he will build the squad with the players of his choice next season. Not expecting much from PSG in the Champions League this season. However, I think PSG will be one of the most worthy contenders for the Champions League title next season.