I guess what's surprising to me here is that in a nation of 1.5B people, they only have 250M homes.
Edit: Given this - it seems like China might be able to more easily absorb this many apartments being put on the market. One could imagine a lot of people entering a modern world where they wouldn't live with their parents (or child).
[1] https://www.statista.com/statistics/278566/urban-and-rural-p...
Still, I'm sure there's a bunch of people that only live together on paper, or multiple families that share a house because they're poor, and the like.