It is clear that currently it is difficult to find a striker who has abilities as good as Mbappe, but football is not just a game for 1 player but 11 player, so when PSG is able to find a suitable and compact striker in their front line, i am sure that PSG will no longer be dependent on Mbappe. Actually, Neymar is also a very good striker but his ethics are not good, Enrique is quite an experienced coach, he must be able to prove himself to make PSG much better than last season even though Messi and several other star players are no longer at PSG.
PSG's current position is in 2nd place in the Ligue 1 standings, they are below Monaco, which has a much cheaper player value than PSG.
The media has tried to play up a much bigger issue concerning PSG and Mbappe, as if without these players PSG can't do anything. Luis Enrique can prepare the best squad for PSG for the next few seasons and if management gives him time then I'm sure PSG will be even better in the future, especially when they play in the Champions League. Now what he needs to do is find the right replacement on the front lines if Mbappe plans to leave next season and they also have to get used to being without Mbappe if they want to achieve success in several competitions.
I agree that Mbappe has an important role in the PSG squad and he is one of the best players at the moment in terms of scoring goals and playing skills. But PSG can't hope for Mbappe forever because every player wants to play at a different club to achieve their individual career. Currently they are two points behind Monaco and Luis Enrique's job is to focus on winning the next match.
I think the matter of Kylian Mbappe's future isn't supposed to be the a case of discussion now that the transfer window is over. Kylian Mbappe is a Paris Saint Germaine player and will continue to be their player till the end of the summer. Luis Enrique has been given all the necessary backings he needs to succeed in his first season as a PSG manager.
Though Mbappe wants to leave the French capital to continue his footballing career, but it's been reported in the media that he's going to sign a one year contract extension with the club so he can be sold for reasonable amount of money when he'll be leaving next summer.