Back-to-back title is quite possible for Manchester City when we think about it on paper. Because technically they have one of the best squads in Europe now. And they are playing according to Guardiola's really solid system as well. However this task is still going to be quite difficult for them at the same time.
The reason why is that they have really challenging opponents such as Bayern Munich and Real Madrid. Manchester City won the title for the first time in their history previously. It would be really challenging to retain the title against these more experienced teams.

De Bruyne and Haaland are needed as a duo for Manchester City from now on to increase their chance.
if champion league still dificult can back to back manchester city this season.
There are still strong teams with many stars and winning traditions in the champion league. for example there are real madrid, bayern munchen. PSG, although it is not the first tier superior team, should also be aware of the many star players there including Mbappe. although PSG does not have a winning tradition in the champion league. but still need to be aware.