There is enough vacant housing in China to house Spain. Prices are going to drop, probably.
It’s better to look at this from China’s vantage point. Truly, enough housing to house Spain is not enough. Perhaps for Spain it is, but we’re talking about housing China - 1bn people.
As for tech, I don’t think we’re even close to saturating the globe with technology. We’re in such an infancy that we literally need something like Starlink to get everyone connected.
We’re nowhere close to it.