There's a weird dynamic in that squad and it ain't good.
TBF it's not weird, it's just constructed poorly. The forward trio is amazing, but - despite what the fans might tell you - they don't play defense over extended periods of time. PSG is defending with 7 people. Hakimi was also getting destroyed defensively.
Their midfield needs to be some prime KCM thing to work (and even they had Benzema always working hard, even Bale - let's say Ronaldo didn't exactly ruin himself defensively). Some of their midfielders are bang average players for this level, but some are good - but ALL are set up to fail. Hakimi bleeding on the right side, forwards not contributing defensively - and, with no Mbappe, very limited speed.
Also, not impressed with Nagelsmann and some of the Bayern players. Koman was amazing, De Light rock solid, Chupo Moting a threat... Musiala had flashes, but no more than that. Sane was poor and Gnabry looks like a peasant version of Gnabry from the Kovac years.
Nothing's over yet, tie basically hangs on Mbappe's health. Messi, Neymar, etc... Won't matter without Mbappe. But if he's ready for the return leg, Bayern could be in trouble unless they adapt.