This problem will not be solved until other clubs find wealthy owners. How likely is that to happen? I think it's extremely unlikely, so PSG will continue to dominate Ligue 1 for a very long time to come. It's a huge achievement for them that they finally won the Champions League and proved that French clubs can compete at the highest level.
What's our main problem? PSG will continue to dominate Ligue One until these French teams understand what's going on here, ensure they invest heavily and get grinded in the football transfer window, get the best players to compete with PSG for Ligue One domestic trophies. Because it's becoming a clearer picture of painting other French clubs as relenting ones and not determined.
French clubs have been underrated over the past decades following their incompetence in the elite tournaments and not only in the domestic league. We know it's been quite one hell of run for Paris Saint-Germain to win the UEFA champions league, we know it's never an easy race. PSG manager, Luis Enrique is a tough man and will always know what he wants and that's simply sticking around and winning games and trophies for the club.
As I already said, the problem is solved by wealthy owners, which only PSG can boast of at the moment. It's somewhat similar to the Bundesliga, where Bayern Munich has dominated for a long time, but there are significant differences here. Bayern is a well-established team, a winning machine, but PSG has long been buying good players and playing with what they have. Obviously, high-level players are unlikely to play terribly and lose. And it was precisely last season that this problem was solved.