In Tibet, people were not too happy about the military presence on the streets, the cultural assimilation or the mao statue in the shadow of Potala palace, but on balance are were happy to be part of China due to the economic development. People felt they would be unemployed without han presence.
In Hong Kong, the most common thing I heard was vaguely racist grumblings about mainlanders. People were unhappy with mainlanders behaving in an "uncivil" manner. There was a majority acknowledgement of China's sovereignty over Hong Kong, and a strong "Chinese" identity.
In Taiwan, things did fit your narrative pretty closely. People want nothing to do with the CCP, and many even wanting nothing to do with the mainland at all.
https://en.wikipedia.org/wiki/2020_New_Caledonian_independen...
I agree with you on the principle of the right to self-determination, but it's not so clearly defined. I.e. how do you define "peoples'? I can't succeed from my nation just because me and my family would like to start a principality. At what point does a group become a 'people' deserving of the right to self-determination?
If California might have a small risk of voting to leave the US do you think the government would hurry and let them vote or try to block it?
I cannot think of a single example where there was a vote of independence where it wasn't either forced (by unrest, war, etc.) or the result was know or didn't matter much. Votes of independence are rarely happening under nice circumstances.
https://en.wikipedia.org/wiki/2020_New_Caledonian_independen...
or of course:
https://en.wikipedia.org/wiki/2014_Scottish_independence_ref...
Really interested to know when did you talk to the people in Hong Kong. What you described might have been the views of some Hong Kong people 10 years ago, but it's definitely not the mainstream view nowadays.