And arguably, they already extracted the value of that house by having a place to live without having paid for it up front. They didn’t even put up the capital in most cases. In the US they will have been granted a loan that is backstopped, and therefore subsidized by the government. Don’t forget the mortgage interest deduction, that’s a massive homeowner subsidy.

So someone else put up the capital, the government made that capital cheap, and societal demand with artificial scarcity (in most places) pushed up the asset value.

I’m not saying it’s a bad thing, but let’s not pretend that making capital gains on a house in the US is anything like any other available investment.