Acres? Those are bona-fide mansions and estates.

The definition of McMansion I’m familiar with, at least in Los Angeles, is demolishing a 2bd/2ba bungalow to build a 5bd/4ba house, usually by getting rid of all fertile backyard/frontyard in the first place. They have another pejorative name, too— “Boxy Moderns”

This is super common in Santa Monica or Beverly Hills, for example. Even San Francisco!

And yet, for some reason, this is completely fine to build without any zoning meetings but the second you propose a 5-unit 1bd/1ba apartment building with the same profile in a “single family neighborhood” it’s ruining the entire “character” of the place and requires 3-5 years of bureaucracy and, depending on the neighbors, litigation.