Winning the France League title is a regular occurrence for PSG but their main target is the Champions League trophy which they have so far failed to win. They kept players like Mbappe and signed big name players like Messi to their club only to win Champions League trophy but to no avail. The team was eliminated early in the Champions League after losing to Bayern Munich in the UEFA Champions League. Until now they believed that they can win the Champions League trophy but now they may not have that belief because Lionel Messi has left the club, Neymar may leave PSG and Mbappe is likely to be signed by Real Madrid. Sergio Ramos may join the Saudi League. If these key players of the team are gone, it will be difficult for them to win the league title.
I don't know if Neymar can find himself a team in Europe at the moment. His contract expires in 2025 so interested teams have to pay a transfer fee as well. The reason why I stated it is that his market value is still 70 million euros. Of course PSG wouldn't demand that much for a 31-year-old player. But I wouldn't expect them to demand less than 40-50 million euros anyway. Moreover as far as I know his current salary is 36 million euros per year which is an enormous sum.
I don't know if there would still be a team to be okay for meeting all these demands. Hence I expect him to stay here for a long time unless he gets an offer from outside Europe. As for Mbappe I don't expect him to leave this summer either. But for next season it is doubtful. If PSG fail in winning the CL title again then maybe we might see him at Real Madrid right after that.