> The chaos of people being able to build whatever, wherever, is probably why Seoul and Tokyo both have remarkably reasonable rents relative to their size, prosperity, and national importance.

I think the premiss is not true. They cannot build whatever wherever. They have different zones, which determin, what kind of buildings are OK to be build in them. See for example this video: https://invidio.xamh.de/watch?v=wfm2xCKOCNk

But there does seem to be some increased flexibility.