Not big on the inhaler nonsense, I think it is a weak argument similar to calling us cheats.
They have done well due to lot's of off field improvements just as we have, the modern footballer is under scrutiny to be the best he can be and that's the difference between being good/better/ elite.
In lot's of sports the very best get accused of doping/cheating call it what you like but I bet you a pound to a penny the ones saying it are sat on their arses while the elite are doing everything they can to be the best they can be.
If I sat on my sofa with my inhaler all week I still won't get close to the player who trains every day without fail.
Top and bottom of it is they are good but City are much better in every element of preparation and bringing it to the table.
I wouldn't dismiss it as 'nonsense'. The boom-bust nature of their fortunes isn't exactly ordinary. They're a team that got 97 points in 2018/19, 99 points in 2019/20 and then 69 points in 2020/21. No doubt teams can have an off-season, but the equivalent of 10 wins being turned into defeats between campaigns? Even then, they rallied to win their last eight games in a row out of nowhere. Before those eight games, they went from not having lost at home for FOUR years to losing SIX games in a row. Normal? Even in our 'off' season of 2019/20, we amassed 81 points. Hardly impressive but enough to win the league title in many seasons gone by.
Fast forward two years and they go from a 90+ points total and near quadruple in 2021/22 to losing 1-0 at Forest, 2-1 at United, 2-1 at Brighton, 3-0 at Brighton, 4-1 at Napoli, 4-1 at City, 2-5 at home to Real Madrid, 1-2 at home to Leeds, 3-2 at Arsenal, 3-1 at Brentford, 3-0 at Wolves and 1-0 at Bournemouth. Once again, out of nowhere, they then rally and almost get a CL spot.
Now, I don't know what's going on, but that guy's article predicting a slump in 20/21 turned out to be spookily correct. In view of their consistently disgraceful behaviour towards City, they have done nothing to earn the benefit of any doubts I have about their abnormal energy levels.