Buffalo has 50% as much housing now as it did at its peak, since demand dropped and housing was just razed rather than maintained. There are lots and lots of cities in the USA that aren’t San Diego, LA, SF, Portland, Seattle, NYC, Boston, … and they have plenty of supply that there is no demand for. You can buy a house for cheap in Toledo. For some reason, people would rather pay $3000/month to live in San Diego than $700/month to live in Buffalo or Toledo. It shouldn’t be a mystery why.

I lived in Beijing for 9 years so I get a different perspective. But ya, the market for people who want to live in Beijing rather than Chengde or Langfang is surprisingly vast, and Beijing has a resident system to prevent at will migrations.