If it was legal to provide housing in San Francisco in dorms it would be done. If it was legal to build residential skyscrapers in New York Queens would look like Brooklyn if not Manhattan.
Make building housing legal and the market will provide.
I wonder if the following is true?
When you build more apartments you get more density and more inward migration and more concentration of opportunity, until the marginal migrant can't afford or doesn't want to live there. The same sort of people are miserable when there's more density as when there was less, except there's more of them.
[NOTE: I mostly agree with you and this comment is a bit of a non-sequitur but I hadn't thought about the idea that the problem might actually be "moloch" (in slate star codex terms)].
So you will have to build something, somewhere.
Actually, roads and apartments are in counter-balance. More resedential high-rises in semi-walkable distance from business districts and public transit = less roads are needed (but there is still congestion due to bottlenecks). More spread-out houses - more traffic as people will drive tens of miles to work.
Korea is not sufficiently large that you could stick people so far they're not able to come to megapolis and congest it.
They like to designate certain areas to specific industries and then wonder why it's not such a good approach.
Look at Songdo or Pangyo Techno Valley.Both rushed and without much thought. As soon as the gov subsidies ran out the companies wanted to move back because it was both as expensive as in Seoul downtown with little of other benefit.
Also 99% of the companies there were korean anyway.
Korean culture favors one time hit wonders instead of gradual development and continuous improvements.It's the nature of korean culture to just try new things because that is deemed to be better than trying to go with existing ones.
So you build a city and just because you built it you expect everyone to just go there.And it has to succeed or it is deemed to be an irrepairable failure.
Koreans dream of grandiose big projects that will put them on the world stage like Chaebols once did and they dont see the local opportunities or challenges.
Also, putting any number of buildings in the middle of nowhere is not solving any issues. And near Seoul there's no land.
Because roads are practically free to drivers. If you gave me a bigger house for free I would live in it alone even though it was designed for a family of 6.
If you charged a sufficient toll on congested roads the congestion would be gone.
10 years is old but still somewhat livable and generally cheap. Once you get past 20 years, locals basically see the house as scrap. It's really easy to buy cheap houses or apartments over 20 years old. Some clueless foreigners new to Japan see these prices and think they can flip them and resell to get rich, and they're always disappointed to find out it doesn't work that way.
40-50 year old houses can be bought for around car prices if you're willing to live 30 minutes from a smallish city. You're basically just paying for the land at that point.
In some places (or at least the US), old houses generally gain value. Of course, land is valuable in and of itself, but there's no shame in buying a 100 year old house in the US. There's no worry of earthquake damage, generally no risk of extensive mold due to a drier climate than East Asia, nobody really worries about ghosts infesting the home, etc. Plus, 100 year old American houses are quite honestly probably better than the cardboard and paper mache houses that have been common recently. In my experience, 1920s apartments were much nicer than the post 1970s places I lived in.