PSG has no rival in Ligue 1. They have nothing to worry about because every season is like a work over for them. Winning the trophy has become their tradition in the sense that they're used to winning it and will always add it in their yearly celebration activities, because no club can stop this from happening.
The other teams need to start playing with the goal of becoming champions. There are many skilled players that these other Ligue 1 teams can sign to compete against PSG. But what has been happening in Ligue 1 is that the other teams have realized that they can make much more money by selling players. So they focus on signing cheap, skilled players, so that they can then get their attention and then sell them for a very high price.
Take Mbappé for example. He was a Monaco player for 3 years and Monaco loaned him to PSG. As PSG liked him, what did Monaco do? Monaco simply sold him, at PSG he became so important that people forgot he was a Monaco player, so this clearly showed that these other Ligue 1 teams don't want the title, they want to make money by selling players, it's not because they can't compete against PSG, they simply don't want to
I agree with your opinion, and I'd take a Bundesliga club like Dortmund as an example, one that isn't motivated by winning titles but rather by the business of selling players to make money.
If Dortmund wanted to, they could win the title, as almost all of the players they sell are highly talented, like Haaland.
So, other clubs in this league could actually try to break PSG dominance as long as they have a strong desire and focus on winning titles without worrying about the business of making money.