Although they don't have the world's top players like they used to, the other clubs in the French Ligue 1 are much worse. Their players are mostly not comparable to PSG's players, although there may be some who are better, but most are not. PSG's front line, although they don't have Mbappe or Messi anymore, they still have Dembele and also Kvaratskhelia.
The quality of the players in other teams is below PSG players so even though Lionel Messi and Mbappe have left, it does not weaken PSG's strength and in fact they are getting stronger because the front line is much more productive. Dembele is in top form this season and he looks so productive in scoring goals, this is quite an impressive season for him.
Exactly, that's why if PSG wins again in French Ligue 1, yes it's very common, and in fact it's mandatory to win, because if they fail to lift the trophy in Ligue 1, it means that PSG is that rotten. But once again, PSG is rich, lots of money, so they will not be replaced this season or maybe the next few seasons, unless the top Ligue 1 clubs get an extraordinary injection of funds, which can make them able to buy many top world class players. maybe they have a chance.
Even if we look at the statistics in the standing table, PSG is indeed the dominant winner with an unbeaten match. They have 23 wins, only 5 draws, and 0 losses. That means their dominance is very good, even much better than last season, where they lost 2 times last season, and now they have 0 losses.