But to say that Messi did not contribute anything in my opinion is also too much, because he can also contribute, it's just that maybe he did not contribute as expected, that's all. He had a hard time after leaving Barcelona, and indeed it was the first time he had a new team after years of being in the Barcelona squad. And if we look at it, his departure was not entirely his wish, but Barcelona was in a bad situation so they were forced to sell Messi. So maybe one of the reasons why it took him so long to adapt to Paris Saint Germain's game, because his heart was still left in his previous team.
I agree with you, Messi has contributed with Goals and Assists to lead PSG to win the title in the domestic competition, but he was unable to carry PSG to win the UCL trophy because they are still unable to compete with other top clubs. At that time, PSG front line was filled with the world's best players, Messi, Neymar and Mbappe, while in other positions PSG also had classy players, so all players had the same responsibility. Psychological problems can affect his performance, but as a professional player he has done his best for the team he plays for.
Messi was good in PSG, but he joins this club just because of having huge amount after having good share he leaves and gone for another adventure as his role has never been for having any big impact on this club domestic cups they still can win without any big name into their ranks.
PSG management is having dream of winning Champions League which shattered by many times now they are doing nothing for this just allowing coach to keep things on good level and bring stable PSG in this league with having good chance in Champions League into future while bringing few good names are good, but first they needed to have good depth in players performance.
Bringing Victor Osimhen or Kvaratskhelia will be helpful if they are able to have strong strategy which give all players good chance of giving their best never live under shadow of star players.