Actually PSG failed to win the match despite playing extremely well. The reason for this may be that the team has too many star players or there was something wrong in the management of the coach of the team. Which gets the players in big trouble.
I also don't understand why PSG can lose at home to a mid-table team like Lyon, even though PSG have the best players and even in the first half Lyon had one chance to score a goal through a penalty which was saved by the PSG keeper. But in the second half Lyon again made the lead by scoring one goal and that result was able to bring Lyon to victory even though this result would not affect PSG's position in the Ligue 1 standings.
But I think I know why they lost this game, actually, PSG lost the game against Lyon and they could lose this game even if they were playing against another team because the whole team is not in a good situation at all. They are going to lose Messi at the end of this season and Neymar lost the whole this season because he is still injured in the other hand there is some news about PSG changing the coach soon which can surely have a negative effect on this team.
I expected PSG to perform even worse after they got kicked out of the Champions League. When you are a superstar and the only title you are playing for is Ligue 1, I think it is almost normal when you can't push yourself to the limit. That is the disadvantage for PSG and has been a problem for a long time now. They live the whole year for the Champions League, then they get kicked out and they know that there is nothing special about winning Ligue when you have a team that is destined to win the CL. That's why I don't like it when such players go to mediocre leagues because they get paid well. Neymar was a talent wasted and Mbappe is, too. Messi was old enough and has had his career already, but MBappe going. to PSG and staying there for so long is sad to see.