We saw several inconsistency this season from most top teams. City just happened to be one of them. That of City escalated because their decline in performance didn't just affect their position in the CL table but also reflected in their standing in the premier league. I am not sure this devine in performance have to do with format but if that be true a team like Madrid , ATM and Bayern shouldn't be in the playoffs.
To me I see this as a breeze of season because all the clubs in the top 8 worked their way through the first stage of the competition navigating all the difficult opponents that came their way. A team like Aston villa caught my attention how they managed to navigate to top five.
I agree about City being bad this season, they had a terrible period but looks like they might be recovering and if that's the case then we could end up with a much better City coming up and that would end up being a lot better for them. Doesn't mean they will win the league or UCL, they may lose both of them, but they could at least be in top 24 at UCL and do a bit better, depending on who they face, they may go as far as quarter finals or even maybe semi finals, and that is something unexpected during their bad period, but if they do as well as they did in the last two games then maybe they may have a chance.
It's hard to argue about how City will lose, they had a terrible period I agree with that but at the same time they are one of the better teams so it's hard to just say "yeah they are bad" and assume them out, that's not really going to happen, not right now at least, I just can't suddenly accept that and count them out without a doubt.