It's just that in terms of experience and strength they are very difficult because after all when talking about the Champions League with so many big clubs in the end PSG's strength is not able to make a difference in this case.
They are still not ready for a competition as big as the Champions League because after all, even though their strength is strong but when competing in Ligue 1 which is already without any resistance for them, of course this is a surge more when in the Champions League which makes them unable to compete more and only become one of the candidates to qualify from the group phase, not more than that.
But it's true that this definitely needs a process and it's not easy to get up after Mbappe left. PSG needs time to become a strong team again in the UCL like last season, even though they didn't manage to get rid of Dortmund, at least they have shown good progress, it's just that they weren't lucky enough to qualify for the next round in the UCL yesterday and reach the final, that's what might encourage Mbappe to move because progress is quite slow making him unable to achieve the UCL trophy so joining Madrid is the only way for Mbappe to be able to taste the trophy UCL next season, however, PSG must immediately get up and find a replacement for Mbappe so that they can become a strong team that can not only dominate Ligue 1.
The presence of Mbappe or not they are ultimately the same especially for now they are faced with a transition where in the past few seasons they have always made Mbappe a backup but this season they have to try more which makes this even more difficult.
PSG will still be seen as one of the big teams but to talk and occupy a decent position in the Champions League is quite difficult because in the end they always have mental problems because they are not better than some other big clubs in matters of winning mentality in Champions League competitions.