In terms of the depth of the PSG team, Of course they are much stronger than all the team in Ligue 1 so they always manage to maintain their progress towards becoming champion. Indeed, in yesterday match, PSG almost lost, But they still managed to avoid it with a goal from Gancalo ramos in the final minutes of the match. Now the difference between Psg and Brest is 11 point and of course this is a season where PSG can lock up the title early. Maybe when mbappe left for another team that's where psg power in Ligue 1 started to disappear, but I'm sure Mbappe will stay at psg for a long time.
In the Champions League, PSG also performed impressively because in the first leg they managed to win the match with a score of 2-0, so this capital was quite important for them in the second leg. Luis enrique troops will play the second leg in March and they are very ready to steal victory at home to Real sociedad. Maybe winning the UCL trophy is very difficult for them because other team have a stronger mentality than them.
When you can afford to buy bench players that are more valuable than the starters of majority of the league, it is true that you are going to have a big depth benefit. You can have one of the starters missing, and put the bench player in, and that bench player will be better than the main star of the opponents squad.
This is what money brings you, when you are this rich, there is really nothing the other teams can do to beat you. PSG has been nonchalant about the season so far and the tie is of course not something we gamblers enjoy, but at the same time they are still so far ahead that they do not even care about it, they really can't care if that's okay or not, we should consider that the usual stuff. Just let it be.