What's wrong is that I don't live on what is even the smallest per-state average of sqft for a single family home. average yard size is ~4x that. So that's 4x

What's wrong is that I don't live on what is even the smallest per-state average of sqft for a single family home. average yard size is ~4x that. So that's 4x less open space. You're also assuming that all parts of the US are equally habitable. We're doing a lot of work to try and let people live in increasingly inhospitable deserts. https://housemethod.com/lawn/average-yard-size/ https://housemethod.com/lawn/average-yard-size/