I think they could have won the first year they had Messi, Neymar and Mbappe, but it didn't happen. Later, those who gradually left the team became very weak. They seem to be weaker after Mbappe's departure, but you never know, this situation may suddenly be reversed with good transfers. They reached the semi-finals of the UCL last year, and maybe if they are lucky, they can become champions in a few years. I would be very surprised if this happens, but anything is possible in football.
Its not upto a season since mbappe left the team and they have not played a single game after his exit either because a new season is yet to set in after the exit of mbappe so I don't know how you got to measure the strength of the others who you have classified to be weak after mbappe's exit from the team, meanwhile I was thinking that the team is more focused on making up for the space created by the exit of mbappe before the new season dawn's upon them. When PSG had Messi, Neymar and mbappe, they didn't have a perfect team play rhythm and that denied them of the champions league trophy that season.