That's what makes this league not so interesting because PSG can claim the title much earlier before the season ends so the league competition is not so competitive. It is difficult for any team to break PSG's dominance and that is not at all the competition that football lovers expect. To be a competitor for PSG in the fight for the title, it takes a balanced player strength and that is not possessed by Marseille or Monaco so it is difficult for both of them to compete with PSG.
If you look at the Marseille team when facing their opponents they are able to win the match with a fairly large score but when they want to compete for the title with PSG they actually lose their chances, both Marseille and Monaco are both seven points behind PSG so it is difficult to catch up on the points.
As PSG fans of course they will be happy with PSG's impressive performance and they can celebrate their title again. But as a football fan I think a league will be boring if there is 1 team that really dominates. I like Real Madrid but the match will be exciting if there are other teams that can be Real Madrid's competitors like Barcelona and Atletico Madrid. It's the same as City who have won the EPL title almost every season but at least they have one or two competitors that make the league interesting. PSG are really dominating. They are still unbeaten in Ligue 1 and they have a big points difference with Marseille in second place. This is different from La Liga and Serie A. I don't mention EPL because Liverpool also performed impressively this season with a 6 point advantage and still have 1 game left.