Returning to the French Ligue 1, as long as the financial situation of the clubs playing in it isn't as good as PSG's, it will be quite difficult to make the league more competitive. And sometimes, for most Ligue 1 clubs, not only can they attract top talent with large transfer fees and salaries, but even retaining their best talent can be quite difficult.
There is no possibility that the situation in Ligue 1 will change swiftly. Firstly, the only rich club in Ligue 1 is PSG. The other clubs are financially much weaker than PSG. Secondly, PSG management is interested in spending a lot of money. They want good outcome. And PSG has already shown that they are ready to spend a lot of money for this.
Even if the ownership of a Ligue 1 club changes suddenly, it will take a long time to change the scenery of Ligue 1. If the owner is rich, it is also unlikely that he will provide large funds for buying players. At the end of the day, every club owner do business. They want to make a profit.
Moreover, it is not easy to fight for the title by strengthening the club. It is a long process. A strong squad is needed as well as an experienced coach. Slowly, they may be able to improve. But suddenly it is not possible.