I have been meaning to post some thoughts on Chelsea recently, but I have only just got around to putting it together.
As an outside looking in, for what Roman Abramovich represents politically, he put together a management team that was structurally efficient and effective when considering the team on the pitch (during the mid to late noughties) as well as the academy.
Chelsea had Bruce Buck as chairman, and Frank Arnesen as Director of Football who was then replaced by Michael Emenalo. The latter was then replaced by Marina Granovskaia. These were a succession people who were extremely effective in their roles. Combine that with a core of players that were technically and mentally strong such as Petr Cech, John Terry, Ashley Cole, Frank Lampard and Didier Drogba. These were supported by Claude Makalele (in the early part of the Abramovich era) and then Micheal Essien. That team was strong to an extent that it did not matter who the manager was in the dugout.
As a United fan, I always felt that Chelsea had the resilience to compete on various fronts whether it was the Premier League, Champions League, and the cups. This was evident when Chelsea did not have a great league campaign in 2008-09, (but still got to a Champions league semi-final and FA Cup win) and 2011-2012 (when they won the Champions League and FA Cup double).
Also, Chelsea and United during that mid to late noughties era were two very strong teams competing against one another and on various fronts. City have not had the consistency of competition against them like what those two teams had. City fans will point to the fact that they and Liverpool reached record premier league points and that is fair credit, but City really had the resources to always retain the upper hand and Liverpool did extremely well in 2018-19, won it 2019-20 and was close last season, but they had a blow out season in 20-21 and they are again this season. City during the disrupted Covid season Liverpool won it, were nowhere near in their points tally.
Without a take over or serious investment in the first team, Liverpool are not going to get anywhere near City now, with their current squad and you do wonder will Klopp get anywhere near again? As for Man City, the question remains, once Guardiola leaves, do they have that structure in place in their operations, that Chelsea all those years in spite of Mourinho leaving the first time around. Will they continue to have sustained success without him as their coach?
Obviously, Chelsea supporters will know a lot more than what I do, but this is just a circumspect view from an outsider.