The reason for PSG they spend lots of money but they can't get anything in the champions league is mostly because they didn't have a good manager and they just bought superstar players while PSG didn't have a balanced team, this situation made chaos in PSG that's why they players couldn't have a good atmosphere in the team to have good performance.
PSG is one of the best clubs in the world, they play well in their league, but when they play in the Champions League, their performance is very poor, the coach doesn't have the skills for playing in the Champions League, they need to change the coach if they want to perform well next season, I see there are several new players already since Messi left the team, I would prefer Zidane to coach them, he was one of the best coaches when he coached Real Madrid, and he won the Champions League
If he can coach PSG, he will know which players to buy to help the team win the Champions League.
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.
But what led you to the differentiation to say that PSG is "one of the best clubs in Ligue 1" instead of saying that they are the best and by far the richest club? That is the issue that is the most severe in Ligue as there is one team that has access to unlimited resources whereas other teams don't have the same resources, which often leads to a imbalance in the league at least in the long run. Someone will now say that Newcastle is richer and didn't win the Premier League, right, but that is why I said in the long run and Manchester City also has access to unlimited resources due to being owned by the City Football Group. Imbalances in the access to financial resources can and will create less competitive environments unless clubs meet on eye-level because they are also financially supported. That is what we might soon be seeing in the Saudi Professional League.