Not only did Lille Monaco also break PSG's dominance in the 2016/17 season, but that only happened once after that PSG continued to win the League 1 title and only broke Lille in the 2020/21 season. In my opinion, league 1 is not very competitive because this league is always controlled by PSG and there are no other teams that really put a lot of pressure on PSG, even Nice this season is not better than other teams in league 1 who only put pressure at the start of the season when entering the middle their consistency weakens.
The dominance of PSG in this league continually remain unchallenged and they have indeed reduced the competitiveness of the league because some how people already know how far other teams can go in this regards PSG is always considered the winners not minding how badly they say it believe they will still end up winning.
Except for the one they lost a few seasons back it would have been on record that PSG maintained the Ligue 1 title for almost a decade without any team coming to contend them or challenge them to the point they couldn't get the league trophy, their games across France is such that other teams are yet to get to their level both in the squads depth and the team strength and form, they reamain the best and this is greatly Influenced by their financial strength which is much more than that of others as they are the richest amongst all others in France.