Obviously players have come and gone from your club, the point was the players you'd expect to have their heads turned i.e. Silva, Aguero, Kompany etc, stayed at little city when usually players from those regions regularly have their heads turned by clubs such as Real Madrid/Barcelona.
United lost arguably the greatest ever player to play the game to this exact phenomena.
We saw reports that even Mancini had money funnelled through to him via fake jobs, if you believe this didn't happen with players, especially during the formative years of your club circa 2008, it's full blown naivety.
United lost Ronaldo to that exact phenomena and thats it. Ronaldo had made it clear that he was always going to end up at Madrid, since he was a kid. He had a career plan in which United were a stepping stone.
I also never said it didn't happen with players (though its highly, highly unlikely given everything else that leaked from the club) I said the myth players never want to leave City is just that a myth.
When winning trophies players don't leave. Liverpool had loads leaving till Klopp won the CL, how many of their squad have asked to leave since (I believe Wijnaldum to Barca may be the first one if he goes). There was talk of Salah but its only talk, the same talk that comes up about Sterling every year.
Saying why didn't Kun, Silva, KDB, Kompany leave City is like saying why didn't Rio, Rooney, Vidic etc.. kick up a fuss to leave United? Because they were winning trophies. Just because Ronaldo did it, doesn't mean every footballer wants the same.
Where were they gonna go?
Where would Silva, Kompany, Aguero have a better chance of winning trophies? At their peaks they wouldn't have gotten in the Barca/Real/Bayern teams. Lets take Kun, Barca couldn't afford him so plumped for Suarez instead. After that where does he go. He's not benching Lewandowski, he's not benching Suarez, he's not benching Benzema with Ronnie at Madrid because of how they worked together. David Silva? Not benching Xavi or Iniesta, Modric or Kroos, maybe midfield at Pep's Bayern? Pep only put him in midfield on chance with KDB. Where does he go? He's not starting on the wing at any of those clubs either. Look at KDB now, aside from Bayern where would he go.
Barca are a mess, Real are dads army and his team beat them without breaking a sweat last season. Juve are a one man team. Again where does he go from City with an improved opportunity to win trophies or the CL (despite Cities failings in the competition so far). Theres only 1 answer and thats Bayern and they had their chance with him and blew it.