Luis Enrique is a very competent coach, he has good experience in how a team works, moreover he has managed the Spanish national team, currently the new players PSG bought (L Beraldo and Moscardo) have started to blend in with Enrique's playing pattern, even though Next season PSG will play without Mbappe but I'm sure they will still dominate Ligue 1 but to reach the UCL championship I doubt they will be able to do that.
I don't doubt Luis Enrique's abilities, but the problem is that in Ligue he doesn't receive a lot of pressure and that might affect his performance, I mean in Ligue 1 he can comfortably win the title every season, while his job is to ensure that Paris Siant Germain can achieve something good in the Champions League. In my opinion, he also has to provide a lot of input to management so that they don't just focus on instant achievements, but they have to enjoy the process of making them become champions in the Champions League.
I understand they have a certain amount of money to do whatever they want, but we can see that up to now what they have done has not been able to bring them anything good. And one thing they haven't tried is carrying out regeneration like Real Madrid has done for example. That way they can have a solid squad not only for a short time, but they can have a solid squad for the long term.