All the teams playing in Ligue 1 are PSG's competitors, it's just that there are not many of their strongest competitors. This allowed PSG to dominate Ligue 1 with all its advantages, but PSG was not always able to defend its title without failing in one different season.
This season PSG is strong and they lead the standings with an 11 point advantage. PSG drew its last match against Rennes, but that did not have a big impact on its title chances. The match against Monaco is more challenging after the previous draw, but perhaps not too important if PSG wants to focus on the Champions League. Winning the match and maintaining a points lead is clearly important, but Enrique will have to rotate several players in preparation for the away match against Real Sociedad.
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.