I would blame Nasser Al-Khelaifi for everything, he invested so much in Kylian Mbappe but it turns out he's not reaping the fruit of his hard earned money. PSG will decline in performance, having to lose one of the most valuable player this season. Luis Enrique will make findings to play top games without his best key player in the frontline. Kylian Mbappe exits Parc des Princes this season and we know his next destination. The Frenchman have decided to be in Real Madrid jersey, they know the impact to follow.
Nasser Al-Khelaifi certainly cannot be blamed for PSG's failure to retain Mbappe at this time, as the owner of the club of course he realizes that Mbappe is the mainstay of the team so far so that indeed he will continue to try to keep his mainstay in various ways, previously Nasser Al-Khelaifi managed to convince mbappe to stay at PSG but of course now mbappe desire to leave is so great that mbappe rejects all offers Contract renewal, when Nasser Al-Khelaifi tried to keep Mbappe but you still blame him, then what if Mbappe left two seasons ago, wouldn't you also blame Nasser Al-Khelaifi for his inability to keep Mbappe in the squad?
I think, only you have been blaming the owner of a team that is very royal and dare to spend a lot of money to keep the squad intact

, losing Mbappe will certainly make PSG's attack dull next season, but I think with the financial strength that PSG have now of course they will try to bring in other players who are as good as mbappe and make PSG again have a reliable striker.