Just my opinion but I think this comment, especially Mercedes part, little bit lacks context. Mclaren in early 2000s never had dominating years as Mercedes did and the moment they had in 2008, not only they created one of the probably most memorably toxic work environements, they also commited one of the biggest scandals of f1. Definitely deserved but not being allowed to bring developments to 2009 car, being stripped of constructors money and most importantly being fined 100 million dollars (around 150 million dollars with current inflation apparently) would throw even Redbull from their domination now and it is definitely not something easy to recover from in the upcoming years. In that sense, i don't think Mclaren and Mercedes have any similarity.
Ferrari post-schumacher era is more similar but again I think Ferrari is unique in the sense of populist nationalism mixed with internal struggle for power. I mean back then this whole Santander situation led Kimi to literally quit F1, and this man is still their last champion lol.
At the end, everything comes back to 2021. None of these teams were cheated out of historic record and expected to just deal with it. I believe their "revenge arc" kind of led them to more extreme concepts of which they couldn't still grasp even after a whole season. I think in AM and Mclaren cases, new blood (like pouching the head of aerodynamics of rbr) has more effect than just admitting they got it wrong bc Mercedes also admitted their concept was nothing like they envisioned on theory multiple times but with the budget cap, you don't have any other option than just trying to improve what you have it on your hand. Though, i don't wanna sound as if i am diminishing what AM and Mclaren had achieved bc outdeveloping your engine supplier is nothing but remarkable and embarrassing on Mercedes side.
My point is not Mercedes didn't make any mistakes, they did plenty of them but while points like Mercedes being used to spend money (but somehow rbr is still the only team exceeded the budget cap), being used to winning and got lazy etc are always listed, them being cheated on 2021, its affects on team dynamics as well as Mercedes' political power is rarely mentioned which is imo the reason why Mercedes is like this rn.