Actually that's interesting, I want to watch Manchester City play without De Bruyne, Rodri and Silva, also Real Madrid play without Bellingham, Vinicius and Valverde. So this could make other teams can win against both of them, unlike people who're predict the winner would be either Real Madrid or Manchester City.
PSG without Mbappe would be interesting too, it's like they have zero chance to win against Barcelona.
Why would you like to watch them without their best players?

It wouldn't be enjoyable at all and it would be normal to see them having extra difficulties because of that. This is valid for every other big team with great players in their squad. Unlike you I would like to see all of these teams with their best lineups.
Manchester City will have full squad against Real Madrid as it seems. But I can't say that for Real Madrid I'm afraid. There are still important absent players in defense. Courtois was actually near recovery but he has got injured once again and he is out for the season now.
It seems that he wants to see the team play without its best players because he wants to see which player can be the difference player in the match, that is quite interesting but it would be more interesting if they played with the full squad because that would make the intensity of the game even hotter. I actually always hope that they will always be able to play their best players, but there are obstacles that we cannot predict, such as injuries and so on.
This match is a very interesting match and we are looking forward to it, even though this happened in a round that we didn't expect, because at the start we wanted to see that they would meet in the final. But even so, this will not reduce the tension when they play, I mean they will want to beat each other, so there is no reason for them not to go all out, especially if they succeed in this match, they will be the biggest team his chance to become champion in the Champions League this season.