Today, they continue to be used to exclude poorer residents from richer neighborhoods through mechanisms like minimum lot sizes (housing is much more expensive if you require 10000 sqft lots, etc.) and prohibitions of multi-family dwellings (which make housing cheaper by allowing multiple households to split the cost of land).
The single family home zoning has the stuff like the minumum lot size and prohibitions on lot splitting or multiple homes on the same lot, which essentially sets a floor price to qualify for living there. And a minimum price will lead to minimum salary requirements for a mortgage, effectively locking out those below that income, hence elitism.
False constrain on housing supply despite population boom causes housing prices to rise incredibly, an increase entirely subsidized by the desperation of the working poor to find somewhere affordable to live.
And additional costs of means of transportation in order to be able to live there, because of exclusionary single-family zoning, residential areas are wastelands of nothing, essentially requiring a car per adult individual. This also significantly constrains people with mobility issues.
Today, they continue to be used to exclude poorer residents from richer neighborhoods through mechanisms like minimum lot sizes (housing is much more expensive if you require 10000 sqft lots, etc.) and prohibitions of multi-family dwellings (which make housing cheaper by allowing multiple households to split the cost of land).