I think carrying a team alone is quite difficult. Mbappe is the best player in the world. But if he doesn't get proper teammates I think he will struggle to develop. I think Mbappe is not like Ronaldo who has the spirit of a leader so he is able to carry his teammates and even brought Portugal to win the EURO cup. Mbappe is a developing striker and he needs support from his teammates therefore I think choosing to play at another club like Real Madrid is the best choice for him for now.
Choosing to leave his old team for a team like Real Madrid could indeed be the right choice for a player like Mbappe, but in this case we also have to see whether Real Madrid itself is willing to buy Mbappe for a price that is not cheap. Because a player like Mbappe is still quite expensive, so any team must really consider the cost issue if they want to take Mbappe from PSG. Apart from that, I also don't know whether Mbappe himself still wants to stay at PSG or will choose to leave there for another team now.