I'm not really surprised with the way Ligue 1 teams are not able to compete with the dominant team (PSG). The way PSG owners invest in their team to acquire world class players is not the same way other teams are investing. You can only think of competing with someone when you have same quality of players they have. But I still believe it is a matter of time before other teams would come up to challenge them as it happens in German Bundesliga last two season.
All of these other teams in the Ligue 1can actually get to contend PSG to the point of winning the league title from them if they put their mind to it and for me such can be achieved through a ling term plan and not coming every season with same stuff and hope to win the team who is dynamic with their team depth and form every season , apart from the money and the financing, PSG puts in the work too so if others are able to nature their team well enough for some period of time, they will be able to at a point win PSG and get the league title.
Even though other clubs in French Ligue 1 nurture their teams to the point where they are able to win the French Ligue 1 title from PSG, that still won't stop PSG from dominating French Ligue 1 because other clubs in French Ligue 1 can't retain their best players after winning the French Ligue 1 title. The only way other clubs in French Ligue 1 can end PSG dominance is if rich investors invest in a few clubs in French Ligue 1 so that they won't prioritise selling their best players every season, which will help them to challenge PSG every season and end PSG dominance.