If that's the problem, why did they have difficulty bringing the Champions League trophy to PSG when there were three star players at PSG in the previous season? Football does not rely on one person, but teamwork is much more needed and the performance of the coach is one of the important factors for success in any competition. So I agree with you that blaming one player is not enough of a reason for PSG to fail in the Champions League because there are indeed many other things that are quite crucial.
I hope Luis Enrique is given the ease of recruiting players as he wants so that he can work well together in integrating the team's strengths. If you look at his abilities, maybe Luis Enrique is the right coach for PSG, it just takes time for him to bring success in the Champions League.
In addition to the players and the coach, even the factor of luck plays a role, why City could not defend their Champions League title, because post-match penalties are more of a lottery where luck plays a big role. Can we say that PSG was unlucky in the match with Dortmund? I think so, they hit the crossbar so many times, although they were definitely stronger than Dortmund. So the result comes when there is a certain chemistry in the team, when everything works out in the best way and even luck is on your side.