Manchester City also just won the Champions League title for the first time, so indeed it's never too late for PSG and that applies to all clubs. But PSG can be said to be more serious for UCL, they recruit superstar players and does not matter with the cost. Previously, Neymar was the player with the most expensive transfer fee. PSG were very serious about signing players but they were not very lucky and now their hope is in Enrique hands, seeing its historical achievements, PSG should be able to be better than the previous season.
I didn't count how long it took Manchester City to finally be able to win the champions league after they turned into a rich club, it must have been quite a long time, not one, two or three seasons after that they won the most prestigious title for these European clubs. Pep Guardiola came to City and needed several seasons to bring this club to a championship. Indeed, he at Barcelona could quickly give the title, but at City it took quite a long time.
So it took PSG a long time to achieve that, Luis Enrique a manager who has enough experience he might be able to change this club not only into a club that is known for being rich but also for achieving it but it takes time, not just 1-2 seasons it can take time, the problem is whether the club owner will have the patience to wait for it, if they just keep changing managers every time they fail in the champions league don't expect a title to be won, look at City who really trusted Pep even though several years failed in the champions league and that trust paid off this year by winning for the first time.