For China, it is just a first tier-cities or second tier-cities problem and eventually it would just be first tier-cities problem. Beijing's solution is Xiongan. By moving all not essential government functions, schools, businesses, and industrial to a nearby new city. We should see the outcome in 10 years. Guangdong maglev train is an extension to this same thinking. By connecting a less developed area to a more developed within 30 minutes to an hour so people can work in Shenzhen but live in suburban Guangdong.
As for Hong Kong, I think the central government has made it clear to the HK administration to tackle the housing prices and warn all the pro-Establishment legislators not trying to hinder the effort. HK government doesn't have sales tax, no capital gain tax, very low income tax. Land sales and property transaction taxes make up over 1/3 of the HK government revenue. At the end of the day, it is the will of the HK government that hindered its effort to tackle the housing crisis. Many politicians are also too close to those tycoons. That's why the central government needs to take a proactive role to ensure the housing issue needs to resolve as soon as possible.