Definitely not against this, since any housing is good, and I hate letting perfect be the enemy of good, but not sure why we are so intent on scaling the concept of a single family home down to 200sqft. Townhouses in NYC have existed for over a hundred years, and generally across the world are an extremely viable concept for dense and cheap housing. It's perfectly possible to build cheap townhomes that can house 6 or…
To an American they're small. To a Japanese person who's used to them, they're normal. They're not "family" homes though. They're "single person" apartments.
Here's one
https://www.chintai.net/detail/bk-C0100888800000109404795300...
Maybe not everyone needs 800sqft+ per person?