Bayern Munich had to lose Manuel Neuer in the match against PSG, but that doesn't mean their strength will weaken, because they still have the option of using Sven Ulreich and Johannes Schenk. Even though these two goalkeepers don't have the same qualities as Manuel Neuer, in my opinion they can be used as backup options, because they are also worthy of replacing the role of Manuel Neuer who is predicted to be out for a long time due to injury.
They are not too bad goalkeepers but are not at highest level. In Champions League, defense is important because if you can not protect your goal and get conceded goals from strong opponents, you will likely not be able to beat them. Goalkeepers are important too and people say they are about 50% of a club strength. It can be an exaggeration but it says about a truth of goalkeeper importance.
PSG had the advantage because in the first leg they played at their home turf, so if this opportunity can be taken advantage of, it is likely that Bayern Munich will find it difficult to play aggressively at the Parc des Princes stadium, especially since PSG's strength has three attackers who are in their best playing condition, so that will make Bayern Munich had enough trouble stemming their attacks.
PSG on paper are considered as a stronger team but again we should check at past seasons. PSG failed in many seasons in many pairs when they were considered as a stronger team.
With best of Neymar, Mbappe and Messi, PSG are dangerous in attacking but in World Cup 2022 and lately in Ligue 1, we saw that Marquinhos can be a weakness of PSG defense. It might be their dead point in matches with Bayern.