Because China has a dual housing system to ensure availability of affordable housing, something almost nonexistent in the West (other than Vienna).

Yes people invest in housing. That's not the point. The point is China has a policy goal of making sure people have access to housing, something again almost nonexistent in the West.

All of the West has social housing subsidised by the government. A quick Google tells me most of Western Europe has a much higher percentage of people living in social housing than China.