I live in San Francisco. It's not particularly "new" as the interview implies. Housing costs have been outrageous here for decades, so the degree to which apartments/housing are now unaffordable is only a reflection of the already ludicrous cost of living. Group housing is a "Bay Area thing" because it is solution to outrageous rents many cannot afford to pay alone. In some neighborhoods where it's possible for people to go in on a share situation in one household, it works, but it's actually becoming more difficult to find not more common, due to gentrification in tons of once affordable areas and the rise of things like VRBO and AirB&B gobbling up space which once existed on the long term market.