I think PSG are too selfish and possible because their selfishness means they will lose Mbappe next season without getting anything, even though if PSG want to let Mbappe go this season they can get fresh funds to be able to bring in other players.
Sooner or later, Mbappe will definitely leave PSG and start his career with his new team, and I'm sure Mbappe really wants to join the Real Madrid team because it is possible for Mbappe to achieve everything in his football career with the Real Madrid team.
It's not too late for PSG to get fresh funds from the sale of Mbappe, as long as the transfer market hasn't closed there is still an opportunity for PSG to add to its account balance. Mbappe attitude of not showing good faith in the proposed new contract made PSG even more eager to let him go. Of course Mbappe will leave PSG, now Real Madrid and Liverpool are trying to sign him, if Real Madrid doesn't move quickly maybe Liverpool will be at the forefront of the hunt for Mbappe.
Mbappe isn't not showinggood faith or anything, he is trying everything he can to squeeze every penny out of his situation right now and both Real Madrid and PSG know that and are now figuring out in how far they should play that game with him or not . He will win either way, but winning is not enough for him. He wants to win big time even though he is the best paid soccer player in Europe already. If everything works out according to his plan he can actually compete with the guys playing in Saudi Arabia.