He's never been sacked because he's basically always worked at clubs full of stars incumbent at the pinnacle of weak leagues, or with infinite money. Even City were already champions before he got there.
He likes to make a big song and dance about how he needs to change things up at City because he needs a fresh challenge and new stimuli, to forever be improving.
He should try to improve by fucking off to a mid table club, let's see him win the league at Nottingham Forest.
Or what the fuck, just try working at a club that doesn't add insult to its riches with actual systematic corruption and flouting of the rules. Let's take a few trophies off him.