what you say is true, and also very strategically correct
your technical contribution and your analysis are very intelligent
however what is missing in this trio is a strong synergy, individually they are very strong but together?
Not always great champions manage to do well together, if they succeed they become unstoppable
Sometimes you do not need all three of them to be great together. We all know Neymar and Messi played together and if the two of them play a great game together where Mbappe is bad, then it will be fine and they could still score together, they could have a great play. We also know that Neymar and Mbappe have been playing together for a while as well, and they do have some chemistry which means that the two of them could play great and if Messi is not then it would be fine.
So, if 2 out of 3 plays amazing, they will be better than whatever Real Madrid throws at them, and they can win the game very easily. What the problem really is all about, is the fact that all three could play differently in an individual way and it could be very bad for the team. At least two of them need to work together and find a way to actually connect.