You call that giant? That's an average house, maybe a little above average. Even in NYC, the average four bedroom apartment is 2,700 sq ft- not that much smaller.
An apartment in NYC the size of a suburban house probably costs like $3,000,000. My take is that if you live in Manhattan and can outright afford your rent or mortgage on a place that isn't just a room (I'm sure a middle class single person can probably afford a nice studio), you're rich. The 2000 square foot house I live in now is really big for two people. Then again, I grew up in a 4000 square foot house and can understand how many people see houses under that size as relatively modest.