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.
PSG is the richest club in Ligue 1, so it's no surprise that they consistently dominate. PSG's owners invest in quality young players, something other clubs in Ligue 1 can't afford, as they can only afford players with relatively low transfer fees due to their limited financial resources. Other clubs could be like PSG, but they need investors willing to invest to recruit quality players.
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.
However, I think the quality of the Bundesliga and Ligue 1 is different. Although Bayern Munich dominates the Bundesliga, the competition in the top three is also very tight. Dortmund has always been Bayern's strongest rival for years, and now Leverkusen also became a competitor for Bayern. In Ligue 1, I only see PSG as the strongest.