PSG has only one obstacle that might make things complicated for them. Chelsea is the only club that have defeated PSG in their best form and I believe that if they clash early in the knockout stage, PSG might find it difficult to win Chelsea. However, there are other strong clubs that van stop PSG from defending the title next season.
PSG simply needs to improve their emotional state when they lose early against any opponent. If they immediately show their emotions just because they can't take the lead early, their opponents will easily exploit them, leading to a crushing defeat later in the match. I truly didn't expect PSG to lose so badly against Chelsea in the Club World Cup final, but in the Champions League, I don't think the same thing will happen to PSG again if they no longer let their emotions play out after losing early in the first half.
I don’t know where Chelsea got their motivation on the day of the club world cup final because the way they outclassed PSG still surprises me, every other team will get frustrated by the wat Chelsea attacked them and left no chance for the opposition side to find their way back in the game but you are right that PSG got emotional and forgot how to play and win tough games and it was the start of their failure in the game. They could have done better by controlling their emotions and keep their head and focus
inon the game.