City is a great club. But this season they seem to be having difficulties when their main players are injured. This can be seen from their last 5 matches when Haaland and Kevin De Bruyne suffered injuries. I'm afraid they won't be able to go further in the champions league this season. And for PSG I agree with what you said that they only have Mbappe as a world class striker although I also don't underestimate Dembele. But the problem at PSG is how Enrique makes collective team play because I see that currently they still only rely on one or two players in their game tactics.
The candidate to win the previous season will be the heaviest burden for Manchester City because they have to try to defend the title amidst quite tight competition. Losing Haaland doesn't have a big impact on Manchester City because they have a number of other players who can score goals and Manchester City also have a number of good forward players at the moment. I really agree that if Kevin De Bruyne doesn't play it will have a big impact on the course of the match because Manchester City is missing a creative midfielder who is able to provide measured passes and also score goals.
The chance for PSG to win the Champions League this season is quite small because a number of other teams are much stronger than them. Luis Enrique needs to prepare his players more maturely and may need several additional players in the next transfer market. Mbappe will not be able to provide anything if the support from his teammates is not there and therefore collective unity is needed if he wants to be successful in football.