Apart from what you said, I think we also shouldn't directly say about a setback for the PSG team because that hasn't happened after Mbappe left for Real Madrid. Because PSG still has time to think in order not to experience a setback in its performance next season and apart from that, I also agree with what you said, PSG can still dominate Ligue 1 even though Mbappe is no longer in their squad next season. However, I also hope that other teams can take the opportunity to move better in order to match PSG's strength in Ligue1 next season so that Ligue1 looks more competitive than last season.
Ligue 1 is and has never been a problem to PSG rather the champions league is what they are willing to give their all for because that's one trophy they admire so much and yet have not been able to win it recently. One thing I believe mostly is that mbappe was an advantage to PSG mainly for the champions league and not their domestic league actually, in their domestic league, PSG can always find a way around been able to win the title and even if they don't win they will have a place athe top so for getting to win the champions league some day they would when they must have built the team way beyond.
PSG ambition to win the Champions League trophy will not stop after Mbappe departure, PSG is still trying to realize their dream of becoming the number one club in Europe for the first time in their history. However, this is not as easy as turning the palm of your hand, we realize that PSG is financially capable, but will not be able to speed up the process of realizing their dream. Building a solid foundation, by remaining the most dominant in Ligue 1 every season, can increase their chances of winning the Champions League trophy in the future. Luis Enrique has a wealth of experience in managing a club, PSG should keep him for a long time, who knows, in the future this collaboration will produce the expected results.