Surviving in Ligue One is simple, there are limited challenges for Les Parisiens and that put then in a better position to win matches and titles because they're top club. If PSG could sit in the position to duplicate Kylian Mbappe, they will without hesitation, winning will become constant. Paris Saint Germain have risen from the top lead, they have started to settle for lesser outcome which weigh below their standards. PSG once upon a time had brilliant top names in the club but they couldn't hold tight of the club, resulting tem to become vulnerable to their opponents and they easily lost matches.
The dominance PSG has over other teams in the Ligue 1 is such that in the current season, no team will be able to displace them or take over their dominance as they are tops both in performance a.d the goals they have gotten so far in the league so they are still maintaining the top position in the Ligue 1 for awhile till other teams prove otherwise.
PSG is very likely to win the title this season again as they have done most often in recent times but the UCL will be their biggest challenge especially with the exit of mbappe who will most likely be leaving soon except otherwise, he is a good player and most teams across Europe would like to have him but I don't think the premier league is a place for him because the competition there is way much more than it is in the Ligue 1 so he is going to need much time to adapt to the style and pattern of play in England.