> White flight and urban decay already happened though. Why are people moving back?

Jobs.

"White flight" is also a US phenomenon, yet over-urbanization is happening everywhere. Look at Japan for an example. And it's a mono-national country without any significant internal racism or segregation.

Tokyo is also a nice counter-example for many proposals. It's building new housing as fast as possible (whole neighborhoods are construction zones!), it has a land value tax, it allows microapartments, it's building transit all the time. Yet nothing helps. Housing prices keep rising.

> I believe the reason for the unrest is that technology and the attendant wealth consolidation have greatly outpaced our social systems and constructs.

And over-urbanization is one of the reasons this became possible (not the only one, but definitely a contributor). An average company in a small town can't afford to treat people there like shit. They simply won't have any workforce or customers after a while. A company in a large city always has access to a pool of candidates.

> But spend some time in the Eixample area of Barcelona if you get a chance.

I grew up in Russia and Ukraine, and I also lived in Europe (Germany and the Netherlands). I got my driving license at 27 years and my first car at around 30 years of age.

And Spain has all the same problems as other countries: large cities are unaffordable, and small cities are dying. It's more relaxed in general, but the trend is unmistakable.

> Life should be easier for people.

Yes, and the only way to do that is to look at the root causes.