No matter how much teams improve, they can't improve as much as "I can spend 100+ million if I want to" type of PSG, that's just not possible. What PSG could do if they want to do, is not what other teams could even dream of and the difference is huge.
This is why I believe that we can't really expect other teams to do well. Even if they do well for a short burst, like how Lille won it once, I think it's clear that we are going to see them sell all their good players and that's going to end up hurting their situation a lot. I hope that we could make a change from it eventually but we will not and PSG will continue to end up with their winning streak, not just game, but also seasons as well, they will just keep winning.
PSG is the only team that has unlimited financial power in Ligue 1, while other teams may not have half the wealth that PSG has, so it is not surprising that the competition in Ligue 1 has not been competitive so far, I think with dominating Ligue 1 which only has weak teams for PSG it actually makes PSG strength weak when they have to compete in European matches, because the performance of players and teams will not improve when they only face weaker teams, but one thing that has been quite surprising to me all this time, why Ligue 1 can become 1 Among the world's top 5 leagues in the world?
whereas don't find any competitive competition between clubs there, in fact if you watch the Eredivisie league it is actually more interesting than Ligue 1.