> I've never understood how real returns on house prices could be believed to be sustainable. If the value of a house appreciates in terms of purchasing power for some other good at a constant rate, at some point in the far future just a single house would become valuable enough to purchase the entire global supply of the other good.

This is likely on me for misunderstanding your comments, but if housing costs increase in line with inflation then everything else will get expensive too. The relative cost of other goods will be constant, and we would never reach a place where a single house could be so relatively valuable.

Unfortunately, house prices have been outpacing inflation. This can't continue forever. It's being propped up by laws and policies and special tax exemptions, but eventually the majority of voters will live in rental accommodation, and they'll vote for policies to bring house prices back in line with inflation.