The problem isn't Luis Enrique per se or the players he has or has not coached, the problem is that Barcelona was on full steam back at the time because they were pretty much in their prime and they had a competitive league and the rivalry with Real Madrid that always kept them going harder and better. PSG is a lone wolf in Ligue 1 and they have all these average opponents and then suddenly they face teams like Manchester City. For PSG the gap in required performance between the competitions is huge and that can be a disadvantage when they are required to deliver.
Agree about your statement about the PSG and their biggest problem why they are not having success into Champions League with right now we have nothing right solution for them about their problem mostly French clubs are having problem no investors are ready to invest good amount which bring their quality and performance at the better level and French soccer authorities are also failed to bring anything positive for the investment just because of this many clubs are suffering and having inconsistency into their performance even many which were at the top spots now having tough time and suffering badly into relegation zone.
Here we need good and solid ideas which bring good attraction for the investors and with this all they have good investments which bring quality players and good fight at the top ranks which also improve their mindset for the Champions League and other top clubs in other leagues.
It's certainly one problem, but in a mediocre league like the Ligue 1 this problem is never easily solved. Investors can't pimp the league such that there are several PSGs. The Premier League and sometimes La Liga are the best leagues with the highest potential for strong competitive games domestically. France is quite low there I suppose.
One solution might be a star coach like Pep Guardiola. I think he would be the right man to keep up the tension no matter against which team they play in Ligue 1 to then be ready for the big games in the Champions League. I think even Enrique is not good enough and probably too soft.