Single family zoning was invented with the Chinese in mind. But much of American zoning post-WW2 is a reaction to the Great Migration and concomitant phenomena like redlining, which created new neighborhood and municipal borders that were defended in part by shrink-wrapping inhospitable zoning codes around existing residents.

A good starting point for reading about this is "Harland Bartholomew". He's the architect of what turned out to be St. Louis's ring suburb design, but he also traveled the country building these de facto redlining codes all across the continent.

It's not a red herring.