Perhaps its because the average house (e.g. the Simpsons house) is no longer achievable for the majority of young people, smaller footprints mean things have to become multipurpose.
Looking at the trends for home size, it seems like those size homes, 2000sqft+, only started getting built relatively recently, so it's not as if they're some kind of human right.
How did people host before 1990, I wonder?
How do people host in Europe, where the average home size is still relatively modest?
It's relatively rare to host anyone other than family in European countries. In asian cultures you commonly host people at restaurants / catering halls.
Smaller bedrooms, smaller kitchens, smaller every room. My grandparents' house's rooms were small in every direction, but the entire house still fit a dining room with room for 8 (snuggly), family room, living room, kitchin, bathroom, and multiple bedrooms.
> I spend remarkably more waking hours in these locations compared to where I sleep.
That's good. For sleep health, your sleeping room should ideally be used only for sleeping. Don't work, read, watch TV, etc. in that room. If you work from home or need an office or studio, that should be a separate room if at all possible.
One of my favorite buildings in San Francisco is an Art Deco apartment tower, bordering on an SRO at the time it was built. The residents were expected to entertain their guests in the dining room, lobby, and bar, instead of in their homes. And they did so.
That wasn't the average house which is partly why Simpsons had a whole storyline about how they could afford it. A more likely reason is probably the growth of the single-person households which grew from 6.9% in the 60s to 38% now. People live alone and they eat alone.