The number of star players in one club makes the dressing room situation very difficult to overcome and makes conducive a very difficult thing. Currently, it is like the picture in the PSG dressing room, especially with the presence of Messi, making PSG increasingly dominated by star players, but on the one hand, almost every PSG striker from Neymar, Messi to Mbappe tries to impress by relying on individual skills without teamwork. But currently Lionel Messi is still injured and has not performed consistently with PSG in Ligue 1 and only contributed 1 goal. The situation is quite difficult considering Lionel Messi is the best player in the world today.
it is true that many star players the dressing room situation has become unstable especially regarding the sensitive issue of salary differences,
because the difference in salary makes the mentality of players to each other not conducive. the current problem in PSG and other big and rich club is, clubs can buy star players but can't buy or get trophies. However, buying a star player is a short way to give PSG the chance to pursue the CL trophy they have been dreaming of. Regarding PSG vs Real Madrid I think don't underestimate PSG they might give you an unexpected surprise.
Salary differences will always be a problem during this online world we live in. When it was a bit of older generation, even online world wasn't a big problem but these days the younger players were born into technology and they keep seeing these talks. It is not even about checking and seeing who makes how much, people knew this already, even before the online world it was official numbers that you could see, but nowadays we see the news.
You think Mbappe doesn't see news regarding Messi not even properly playing but making more than him? You don't think he sees newspapers making fun of it? You don't think there are many situations like that? The online world changed so much so that people are reacting to it and it is changing the future of the clubs.