Dependency on a particular player has always led to the down fall of most teams because I'm the case where such player suffers injury or is unable to play for some other reasons, probably had a red card ,the team suffers till his return, it's true that there's always a particular player who's always the game changer for any team but they shouldn't depend on him.

PSG has got very similar situation with mbappe as they have some level of dependency on him even tho they try not to make it obvious but then it could be observed in their performance in his absence how they almost not win games or find it difficult getting enough goals to be able to win games with good margin, this season they have played a few match without him tho but then it was obvious he wasn't in such games as their performance showed as one without their star player been present. For sure if he leaves they are definitely going to suffer the after effect awhile.