Messi's performance this season was not bad at all and considering the current situation of his team where they are unhappy with players and their coach, still, Messi's performance was well enough for PSG but the problem with PSG fans in they are expecting to see Messi performing much better than this and for any mistake from their team they just blame Messi.
What's the point of blaming a Messi, and I think it's a very funny thing if the fans only blame a Messi who basically always plays pretty well in the team he's defending now. Because the good and bad of a team depends on whether or not the people in the team are solid and that also includes the coach, so it is very inappropriate and very funny to only blame one person whose profession is a player.
Fans' expectations for Messi are quite high and when he is unable to fulfill that of course there is a feeling of disappointment and in my opinion that is very natural because during his 2 seasons with PSG there was not much contribution he was able to make to improve PSG's performance on the European stage and when compared to Messi's performance With Barcelona, of course, it can be said that Messi's performance for PSG was a little bad.
I think if Messi leaves PSG then it will not have a big effect on PSG's performance, especially on the front lines.