If what you say is true, about simmering discontent in HK due to conditions worse than in China. Why don't the HK people just move to China? Are there any rules against that?
If not, why are they staying in HK?
If not, why are they staying in HK?
For your question moving between cities anywhere is hard. Moreover most population in Hong Kong is not that well educated to get better paying jobs as locals have better university education and good English knowledge in tier 1 cities.
People live in Hong Kong as they don't have a choice or skills or resources. Most Hong Kong people with skills or resources are already either in China or other parts of the world.