In Ligue 1, what you said is true, other clubs are too weak and barely can have good seasons to challenge PSG and beat this giant club. PSG many times had their bad matches but they still completed those seasons with titles because other clubs are too weak to take advantage of PSG's poor performances. In domestic league, PSG easily won titles but it becomes their weaknesses when they play in Champions League. Being familiar with lower quality of matches in Ligue 1 and weak opponents there, they don't have enough quality, carefulness and preparations for tough matches in Champions League.
Actually PSG performance in this season not really quit well and have losses many points behind 5 draw and 1 loss but still can't manage PSG points by the other teams. Nice on current 2nd standings position remaining 6 points and seems how not competitive of Ligue 1 although the top standings team losses many points but can't pressure by the other team. In Ligue 1 have weakness opponent team for PSG and difficult has consistency performance, usually AS Monaco and Marseille always become competitor for PSG but both teams difficult consistency performance for leading top position standings.
Less compete with domestic league make Ligue 1 teams faced difficult wen playing in Champion League, season 2023/24 have two participants three participants teams but Marseille failed qualify to Champion League and Lens difficult get knock out round place. Left PSG and I don't expected more will lead to final round or PSG have eliminated in 16 round.