that's actually not small (~600 ft²), being plenty for 2 people (having done this myself), and even a third if they were a child.
without even going tiny home crazy, for a single person in an urban neighborhood, a well-optimized 250 ft² (~23m²) apartment is plenty (i've done this too). if stores are plentiful and close, you don't need much storage, which is how all the excess square footage is eaten up in most homes.
It is small for people buying 200m^2 plus a yard and a garage in suburbia. While I was single I lived on 25m^2 too. I once spent half a year in Tokyo on 5m^2. That was fine too.
without even going tiny home crazy, for a single person in an urban neighborhood, a well-optimized 250 ft² (~23m²) apartment is plenty (i've done this too). if stores are plentiful and close, you don't need much storage, which is how all the excess square footage is eaten up in most homes.