for sexample, i’m very critical of u.s. politics and the way the cuntry is run. it’s an epic failure of untold proportions. but i’m very envious of sinkies who have the pap in charge. the pap does good things for sinkies overall. and i don’t mind living in sg or buying a home there. on the other hand, prc is a totally different animal. ask any tiongs who live in u.s. if they hate u.s. politics and some woke policies, they will all say “yes!” but if you ask them if they are willing to go back to prc to live and buy a home, they will all say “no!” not only no, but “no fucking way in hell!” see the diff?
People migrate or stay overseas for many reasons such as work opportunities, studies, family reasons, pace of life etc. Political system is usually not high up on the priority despite heavy emphasis by the media.
There are lots of foreign citizens staying here long term (some are even naturalized citizens) that are still patriotic to their home countries and get upset if Singaporeans speak ill of their native country. Likewise many Singaporeans who are staying overseas and have no intention to move back to Singapore remain loyal to Singapore and speak well of the PAP government (overseas voting tend to follow local trends of 60+% pro-PAP), so again I'm not sure why this phenomena you have mentioned is in any way unique to China.
I personally know of an American who has lived here in Singapore for nearly 20 years. He still believes in American exceptionalism and often makes it a point to rebut others when they suggest US is going downhill, laugh at Biden / Trump, make fun of their racism& guns as well, but if you ask him whether he will go back to US to stay he will also answer no. But that's not because of some nefarious motive or the US government giving him money to spew pro-US propaganda, it's just that his partner is a Singaporean and they sort of like the lifestyle here in Singapore.
At the end of the day, the decisions people make on the country they identify with and where they stay is deeply personal. I don't think making broad assertions based on political inclinations or coming up with conspiracy theories of paid shrills do any good in further understanding the situation. Politics is really very low on the list of people's considerations when it comes to making everyday life decisions.