Many people argue that PSG won because their opponents were weak. Yes, I agree. But their opponents are weakened because they want to be. When looking at the data:
https://www.transfermarkt.pt/ligue-1/startseite/wettbewerb/FR1The clubs I pointed out with the red arrow have sufficient values to have a squad capable of fighting for the title. They are not fighting for the titles only due to the incompetence of the management of these clubs. PSG achieved a lot last season and did not have very famous players; some of their players came from Portuguese teams. So this shows that it is also possible for these teams to build a strong squad with the financial conditions they have and then fight for the title.
It is nobody’s business that other teams are unable or intentionally refuse to build their teams to league champions standard. PSG are a big club with goals and ambitions so they invest so much to achieve those goals. Whichever club that wants to compete will do the same.