Too much expectations was what kills that combination and that's exactly what's happening in Real Madrid but I really hope they know this very fast. Though, we were expecting to see trophies everywhere the moment Messi step into the game but it wasn't, Messi contract was purposely for fans entrainment to make sells of tickets and more money. I can recall his jersey was sold out in 9 minutes worth of millions for people that went in for the jersey.
Mbape was good but a complete distraction between the rest as he is young and the media wasn't helping and I guess that's why Messi interest decline and wasn't interested in the way the club was turning into and he left for another greener pasture same with Neymar. The same thing they are doing right now in Real Madrid, they have to sell some forward at some point or give them out for loan and build the team better, they don't need some of the players they have right now.
You are saying that too much pressure and big hopes can stop team from doing well and you are using Real Madrid and PSG as examples and when team gets much of famous players and it looks exciting at first but with this team not work well together and not win trophies.
Real Madrid are making same mistake with having too many attacking players. This could mess up how team plays together. They need to sell some players to make team more balanced.
It is true that when they have many famous players and it is hard to handle their personalities and what news says about them. It is more important for team to have players who work well together than just having much of star players.