What's worse, the other teams in Ligue 1 are unable to put up a strong fight against PSG in the race for the Ligue 1 trophy. Thus, even though PSG is the best team in Ligue 1, but in reality PSG is still veryweak if PSG are in difficult competition with teams that have another great level in the Champions League. So yes,it's not wrong if you say that Ligue 1 is the weakest league compared to other big leagues in Europe.
I agree with your opinion that Ligue 1 is one of the weakest leagues among the top European leagues. In fact, we can see how dominant PSG is in Ligue 1 and how other teams are unable to compete with them. This is different from other top leagues such as La Liga, Premier League, Serie A or even the Bundesliga which have rivalries in competition. But I think PSG is not a weak team when compared to teams from other leagues. PSG dominates Ligue 1 because other teams are weaker than them, but I see PSG can also become one of the best teams in European competition. PSG made it to the semifinals in the UCL and that shows their level. It's just that they have never been among the favorites to win the UCL in my opinion.
Dont say things like "PSG is a semifinalist, so they're not weak." The only thing that Ligue 1 is good at is one thing: PSG is the league's mascot, and they always look happy. Even though they've gotten some shiny objects (read: expensive stars), what's the point when their own team is so bad? The Ligue 1 is a vanity project with a shiny outside and a hollow inside. The success of PSG is a mirage, caused by cheating with money instead of real talent growth. Its a game that encourages mediocrity and stops real competition.