~Snip
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.
PSG's main problem is not only about not being coached by a great and experienced coach, but they have not built up their squad depth perfectly so far. You can compare PSG's squad from season to season, they are always constrained because not many experienced players in the Champions League have played with them. Last season Messi, Neymar, Mbappe helped, but their midfield was so bad that even Marco Verratti couldn't do much.
I agree the coach is one of the important parts, but another important thing is good squad depth. If PSG have these two conditions, then I think they have a chance to win their first Champions League in the next few seasons. Manchester City have proven that with Guardiola and lots of quality players, so they should be too.