Yes, another reason is PSG doesn't have a champion mentally to face Bayern even has a superstar squad. Maybe because of this reason Mbappe want to leave. As we know, it's not fast to build that mental even have alot of money, The club like PSG, Man City and others is have money to buy expensive player and build the superstar squad and maybe able to stand to local league, but it's not work when fight on Champion League where must have mentally like Bayern and Madrid.
PSG don't have champion mentality at this stage and their performance in Champions League is even worse than Chelsea in the past. Before winning their first Champions League, Chelsea were already a giant there and in many seasons, they brought fear to opponents around Europe.
PSG is oppositely, as they likely are fearful when playing in Champions League. Like in the match with PSG at their home stadium, they let Bayern totally controlled the match. It's a shame when they are a host and played at home.
Having champion mentality without quality players also doesn't make sense to win the Champions League. Bayern Munich have good players to defend and attack, and their style of play is very different and that determines the course of the game. But this defeat was influenced by many factors in which in the end I have to admit that PSG was just unlucky with goals and a few chances.
Bayern always have good players and they are smart to choose players for their team. After the injury of Neuer, they wisely picked Yann Sommer who is a very good goalkeeper and experienced a lot of tough matches in Euro and World Cup with Switzerland. The match with PSG shows that he is a very good replacement for Neuer in short term and long term as well.
Even though PSG has expensive players who are also former Champions League winners such as Messi, Neymar and Ramos, basically the PSG squad is not stable enough in their midfielders. The creativity of the midfield is not good enough to support the attacker where quite often the striker has to go down and build an attack from half of his own field.
Both Bayern and PSG have very good players but as a team, PSG players are not able to unite as a whole solid team and in their team, there are holes that affect them a lot in Champions League. I believe one of biggest weaknesses of PSG is their coach position and they must find a coach who is winner in Champions League like Ancelotti and Mourinho. They have many good attacking players so they don't need to have a coach like Pep or Klopp. They must find a coach who can bring balance for their team by improving their defense.