Pay ~$300k for a house in Tokyo, which will cost you +/- $10k down [+] and ~$1k a month for a mortgage. Japanese underwriting standards would consider this doable at a household income of approximately $2.8k a month or so.
[+] I realize that number is surprising, and I would have found it surprising up until ~3 weeks ago, but I can assure you that this product is presently commercially available in Tokyo, including to people who do not exactly smash Japanese banks' definition of "desirable client."
Ignoring that as a rational choice for many people already in expensive areas is just asking for your proposals to fail.
We very frequently talk about the economic value that could be produced by different housing actions, but policy is not purely determined by economic value. I know more people opposed to upzoning because they like their yards and their space than because they're worried about their property values (denser cities in the US are very rarely cheaper).
I’d be happy to live in a condo, but live in a house instead, because you can’t really build condos here. I’m sure there’s somebody else who would like to live in my house.
No one is ostracized, just confronted with economic reality of competition for space and the laws that distort it. I love living in a house but it’s a little silly to mandate that a house is the only thing that can legally be built on land that’s valued at over $2M/acre.
c.f. https://www.youtube.com/watch?v=iGbC5j4pG9w
[+] I realize that number is surprising, and I would have found it surprising up until ~3 weeks ago, but I can assure you that this product is presently commercially available in Tokyo, including to people who do not exactly smash Japanese banks' definition of "desirable client."