In such big and important matches, it is very important not to succumb to emotions and pressure and to control the game. That is why it is very important to have experienced players in the midfield like Modric.
It's true if experience is important especially he's play at central midfielder position, but he get beaten by a prime and younger midfielders if we talk about the speed and stamina. On the other hands, Manchester City's midfielder have all of those criteria.
That's why, Real Madrid is a good club, but Manchester City is better than them.
First of all, I would say that experience plays a major role in Champions League matches. It is much tougher to perform well in the Champions League if the squad is not experienced enough. And we have seen proof of this in various past matches. And so Madrid needed an experienced midfielder like Luka Modrich in this match. Ancelotti cannot fill Luka Modric's void with any other player.
But if we compare Manchester City vs Madrid midfield then I would say City midfield is stronger. City has talented players like De Bruyne, Gundogan, Silva, and Phillips in their squad. Everyone is a great player. But Modric and Toni Kroos are very experienced. Madrid's midfielder duo is also capable of excellent performances.