@Davian144 when you’re a big club like Manchester City you need to have player’s who can step up and at City it seems that their player’s are not stepping up because these are opportunities for others to secure a starting 11 spot for themselves. Lastly I believe Pep would have done solid analysis by now and will come up with a better tactical plan hence it’s unwise to underestimate City even in the absence of De Bruyne.
Manchester City until now played without De Bruyne and they can still achieve 3rd position in Premier League and won 2 matches in Champions League. They're already been great so far, even though De Bruyne is currently a Manchester City's heart.
De Bruyne will also get older, it's just a part of regeneration and Manchester City seems quite success since they're still in good form.
This is why a team should never be dependent on just one player, because if that player is unavailable, it has a huge impact on their game. But I realize that this is difficult to avoid because it cannot be denied that in a team there are always players who are the mainstay, yes it is inseparable from their abilities and also their contribution to the team.
But can things like this be avoided? Of course you can, one of them is by rotating a lot and also giving many new roles to other players. I know this if done is full of risks, but when talking about risks, this also exists when they don't do things like I said.