So you're basically saying without Mbappe Madrid is not winning the champion League? This is a funny stand because they have done it before without Mbappe so why do you think they can't win without Mbappe, when the Mbappe himself has not won it without Madrid?
Man City has a higher chance of winning but they'll win not because Madrid don't have Mbappe, they'll win because they were the better team. Madrid can also win Man City without Mbappe.
Also, Madrid having Mbappe doesn't mean they will definitely dominate. Madrid has had better players than Mbappe before and they have had better squads than they currently have and they did not dominate in those times. Football is not only about stars.
What if Mbappe comes and the team becomes disorganised? Football is a team sports and for a team to succeed, everybody has to do his job effectively.
Isn't the reason due to the quality of the players? Let's wait and see what strength or luck Real Madrid will use to defeat Man City.
You say that when Real Madrid had the best squad, they didn't dominate Europe. So Cristiano Ronaldo and his teammates at that time helped Real Madrid win many prestigious titles, do you know? Do you know why PSG always wants to use every means to keep Kylian Mbappé on the team? Why is Real Madrid always waiting and trying to find a way to get Kylian Mbappé? And many teams want to own him right now. I know Football is a team sport. Of course, the management board will not let Kylian Mbappé cause the team to become disorganized.
The match between both teams will be a tough one and it won't end goaless, since both of them are quite good with their finishing, it is left for the defenders and Goalkeepers to stop from conceiving many goals.