We have a relatively small house, 916 or so square feet, compared to the national average of around 2300 square feet. But our house was of average size when it was built in 1928, and would’ve had a family of 3 or 4 living in its 2 bedrooms and one bath.
It suits me, my husband & the cats and Rigel, though there are times when an additional half bath would be nice.

Various yarn, stored in English Arts & Crafts bookcase purchased via Craigslist
Dave would dearly love a pool table, since he was a pool shark in college, and if the studio space were big enough the pool table would go there.
Regardless, I think we do a reasonable job of keeping clutter under control (I love decluttering & go on periodic spurts of organizational frenzy) and allocating space in a rational manner.
But I must say, this person impressed me: