They had too many superstars taking big salaries and wages but not all of these players want to take the responsibilities of the club on themselves.
Just to cut a long story short they most players playing for PSG last season relied on Lionel Messi, with the fans having expected too much.
Lionel Messi, Neymar Junior and lastly Kylian Mbappe all had great season, it was just that they wanted all the work of creativity to be done by these players.
Reasons why Luis Enrique will be successfull is because, he is not relying on a single person, he is playing and building a team with no weak link and potholes. He would win the Champions League when the right players have been assembled.
IMO, Messi always took responsibility when he was with PSG last season. even though if we talk honestly, even based on statistics, Messi is the most consistent player of all existing players. The problem is, PSG management is always in control of their team's bag. in fact, my guess is that Galtier was not given the opportunity to bring in the players he wanted. Let's remember again, if I'm not mistaken PSG didn't bring in a single player in the January window last season. "correct me if I'm wrong" even though in reality, this team really needs a creative attacking midfielder.
Maybe that's why Galtier tends to change his patterns and systems. Plus, the sports media always report that in the PSG dressing room there is always conflict between the players. One more thing, the club's mistake for me is that they didn't use the services of a coach with the required experience who could handle a team as big as PSG and control the dressing room. thus, it can reduce conflict between the players.
Now, PSG has appointed a coach who has experience requirements. even so, it doesn't guarantee that this team will win trophies in various competitions. but at least, PSG can still maintain the Ligue 1 title. Even though currently, they are in 3rd place. But gradually, PSG will return to the top of the Ligue 1 standings. Currently, Enriqeu is building his team to have a strong foundation. Plus, some of the new players they have brought in will eventually reach their best level of play. Champions League, not this season. maybe, next season. but at least, PSG has a chance of qualifying for the next round.