Hong Kong has very difficult topography: lots of islands, bays and steep hills. Much of the land is not really habitable, and the government builds very dense, very tall (unfathomably so by US standards) public housing on much of what is.

This is not to say that HK doesn't have a housing supply side problem, because it definitely does, but it's not just the government squatting of vast tracts of flat land.

I suppose it beats the CA housing crisis where people aren't even allowed to live in flats the size of closets, even if many would be quite willing to.

I disagree with this because it solves the exponential wealth distribution problem exactly by making exponential wealth acceptable. It's okay that I live in a mansion where 100 people could live because those 100 people have the option to live in a closet.

I would instead favour making unproductive use of land exponentially expensive through taxation. However I admit the details of how that would be implemented are very fuzzy.