İlkay, De Bruyne, Haaland and Bernardo were on the bench in this match. However, they still managed to beat Chelsea and dominate the game. No doubt they have set the bar very high. We can say that they are the best team in the world right now. They did not even give the ball to their opponents in the champions league semi-final match they played with Real Madrid. They're like Barcelona with Prime Messi. Undoubtedly, they will be the best team in the world for a long time. I can't say anything about Chelsea. They need players who can take on the role of the leading player in the team. I don't know if Neymar can do this job, but there were reports that they wanted to transfer him for a while.
There's no way you can compare the now Chelsea team with the current Manchester City's squad even in the absence of those players you made mention De Bruyne, Haaland and Bernardo. Guardiola has build up the Manchester City team to a world class level, which every team out there will find them difficult to defeat, even at the European level. Chelsea was lucky enough to have conceived only one goal from City, I was even expecting a total humiliation of Chelsea's team at that game today.
What Guardiola has done by building a formidable team with Manchester city, is same thing Ten Hag is trying to replicate at Manchester United.
Pep showed his class as a top builder with Barcelona and as people thought it was because of Messi, he did same with Manchester City. This is one reason why more encounter between Chelsea and Manchester city would be in favor of the latter.
Chelsea, Arsenal and Liverpool should go back to the drawing board too.
Well, the most disappointing of them all is Arsenal, their story is like the story of going from grace to grass, Chelsea's bad performance is quit understandable if you ask me, as I believe we all know that they had and probably still have internal issues, for Liverpool, I can't say as I have really paid attention to most of their games, but for Arsenal, I can't really understand what went wrong with them, they were like going to win the title this season, but all of a sudden, the table turned against them real bad.
Like you said, I hope they go back to the drawing board and find a fix to their problems before next season begin.