I won't deny that money has made them what they are today, but is that the only reason why they can't impress on the European stage? Of course not. We can see from how their situation in the squad, yes they always have problems between one another, be it players with players, players with coaches and others, so with that problem their chemsitry is very difficult to create and the impact on their game is always messy. Star players will not always be a guarantee as long as their relationships are not good,
When you want to create a team just with money and not with a system that happens. City was a good club even before Pep came along, but they became something special with Pep, how come? Because they built a whole system with him and gave him the ropes and tell him to build any team he wants. Just to give an example, if PSG hired Pep tomorrow, and he started to manage that team for a few years, I guarantee you that he will build a team that will win UCL there too.
City took way too long, longer than it should, they had some chances they could have won and got unlucky, it happens and they finally got it, and got the treble along with it as well. As long as PSG doesn't have a system and just throw money at the problems, they won't win UCL.