FOH.
Those cities themselves are unsustainable: SF, Portland, and Seattle are all literal shitholes, due to failed civic leadership and uneconomic policies.
As a civilization, we need to figure out how to reduce the pressure to collect in a handful of places, and spread ourselves back over multiple locations and jurisdictions -- because it's clear that's a better plan.
Our current system is optimized for a few major players, and it's collapsing. They're right to worry, and try to adjust it.
Figuring out how to get people to live in already affordable places is the only way to reduce the pressure on those cities and create housing affordable and livable for average people.
... And thus a bunch of Californians moved to affordable Austin, TX and made it super expensive, driving all the native residents and average day workers out of their homes and onto the streets.
Pressure moved from one location just builds it somewhere else because people tend to congregate. You can't just say "Everyone, go move to remote places in Montana". It doesn't work like that. People congregate around the job markets, money pools, and nice locations. Hence, the coastal states in the US (centers of trade and places with beaches) have the highest population densities.
To be fair, there's a lot of nice locations outside of major cities.
But I agree with you that people tend to congregate around job markets and money pools -- and I think that's precisely what has the wealthy concerned and looking for new models, because the attractive forces in the current paradigm lead to unsustainable attractive blobs.
