This is easier said than done. When you have a squad full of superstars, you can't just sign "any" manager who wants to achieve the club's goals. They did that with Graham Potter and PSG did that with Gaultier. But these guys are not qualified to lead a squad with such big names on the team, you need someone who has experience working with stars and who has won something before. Otherwise it is difficult for the coach to get the respect he might deserve and that is where everything falls apart when the team starts badly into a season.
PSG doing extremely spectacular in their domestic league, the only problem they're facing is they can't record good performance in other top Competitive league like UCL. Chelsea is terrible at the moment, it's very sad to see an elite club. Crumbled in league games both in EPL and UCL. Graham Potter took the whole team backwards and Todd Boehly always have fate that the mediocre coach will turn the team around, but that was on his wrong watch. Chelsea needs an experience coach, and also good chemistry with the players, only then they can perform highly in league.