Outside of KDB, the difference in the quality of the two sides is negligible at best.
Mendy = Ederson.
Chilwell and Cesar are better than Man City's fullbacks.
Kante Kovacic Jorginho are just as good as Man City's midfielders.
Mount is on the same level as Foden.
Defensively, Thiago Silva is more experienced than any City defender and Rudiger is a better defender than Stones, but Dias is probably slightly better than both.
Havertz, Pulisic, Mount and Werner are just as effective up front as Mahrez, Bernardo and Foden.
It's not about who gets in what team. A lot of City players wouldn't be getting in Chelsea's team either, like Ederson wouldn't be getting ahead of Mendy for example. It's about the overall quality and the quality is negligible, if we remove KDB from the conversation.
The huge issue is that this Chelsea team hugely underperformed under a rookie manager previously and it's making people doubt the true quality of this Chelsea side, to the point it's being overexaggerated.