The problem with all of these seems to be: where could you actually live in one in any city or suburban area? I don't reckon you can just buy a small plot of land on a residential street in San Jose and plop this down, hook up utilities, pave a driveway, and live in it. I doubt any homeowners here would want it next to them. I've never seen it done in the Bay Area. Is it possible?
The idea is beautiful, living "in a box" is sure something complex because of the regulations.
But I remember very pleasantly a holiday in one of these prefabricated (in Sweden): with a good (big and serious) design work and targeting the recreation market they could even raise prices.
https://www.studio-shed.com/