What do you mean by PSG not having good quality players this season? Are you saying that Kylan Mbappe was the only quality player PSG had? Most of the key players of PSG like Dembele, Marco Asensio and Lucas Hernandez. These are still good players that are first squad even in their respective national teams. PSG is perfect in their local league just that they are yet to retain good status in European competition Although it is too early to say and I believe they still stand a chance at that because the competition is still very early.
Correct, only Mbappe is the quality player PSG had.
Asensio and Hernandez aren't good anymore, because if they're perform really well, their ex teams will want to keep them. Real Madrid and Bayern Munich are top tier teams, they're not deserved to be compared with PSG.
Dembele isn't even the best player, but he's ego is like Mbappe. It's make sense for Mbappe become selfish person because he's the best player.