They are currently considered the favorites to win next year's Champions League by many betting sites. Paris Saint-Germain is a fantastic team and could be in a very good position next year. They may have lost the World Cup final against Chelsea, but that doesn't make them weak or ineffective. They will undoubtedly be the sole favorites to win next year's French league, and they will also be fighting for and potentially winning the Champions League. Of course, a Super Cup match awaits them, and they'll likely start the season with a trophy.
The loss against Chelsea will have a psychological effect on PSG players because they were invincible before the competition. Almost everyone thought they would win, but they lost in the finals shamefully. Maybe the club will need some rejigging that can be done by bringing in a few new players. The club still has time to build back its confidence, and I am sure Luis Enrique knows what to do.
.However, on the other hand, I believe this is not just a financial issue; it also concerns the club's motivation to perform better and achieve more success, both domestically, in Europe, and globally. The motivation of other Ligue 1 clubs to build strong teams is still considered insufficient. They can build a strong team without having to spend a lot of money. Some Ligue 1 clubs are known for developing talented young players. If only they could retain their best players, perhaps their strength would be enough to match PSG's dominance.
You have brought to light a good but underestimated observation. Clubs don't always need big funds to do well and we have seen that in my Clubs. Leicester United lifted the EPL with a less expensive team. In the 2022-23 season, PSG won the French League by just one point. Lens would have won the league if not for some mistakes that cost them points. Lens didn't have an expensive squad, but they were hardworking and dedicated.