To be precise PSG is one of the best clubs in Ligue 1, I don't want to judge PSG as one of the best clubs in the world because they have never even won the Champions League trophy. PSG's shortcomings so far have been because they are not held by a great coach who is experienced in the Champions League, the attitude of PSG management which seems difficult to bring in a great coach makes it difficult for them to compete with other clubs.
The arrival of a great coach does not guarantee that PSG will immediately win the Champions League trophy, they must wait at least two years for PSG players to blend in with the style used by the coach. Zidane can be used as a solution to overcome problems that have not been solved so far, PSG management must act immediately, they also need to be jealous of Manchester City who have just won their first UCL trophy.
I see that there are not many coaches who dare to take too big risks, what I mean is that working as a PSG coach means accepting the demands of winning the Champions League. If in a matter of two or three seasons you can't win it, then get ready to be kicked out. They don't think about investing in potential youth players from the academy, and trust them to prove their quality. The PSG management and the owners in particular want instant things, bring in star players so they will give you trophies. At least in fact that's how PSG built their squad with their money.
Thiago Silva, Ibrahimovich, Pastore, Di Maria, Veratti, Cavani, Messi to David Beckham who they brought in were among the stars, their big names didn't have a big influence on the club. This means that they cannot lead PSG to win the Champions League and can only win the Ligue 1 Champion. Another fact is that their former captain David Silva himself won the Champions League with Chelsea after leaving there. It is a fact that training or playing for PSG is very difficult, because you are always required to win every game. Luis Enrique has been officially appointed as their coach for the next two years, this means Zidane will have to wait until Enrique is out of contract or is dismissed.