Downtown SF manages to have tall buildings. And there are a ton of 5+1 or 6+1 units going up, which in itself will 3-4x density from height and from smaller setbacks.
> Density means accepting smaller
Strongly disagree. You can still have 1200+sqft apartments. Most of the 2 and 3bd luxury apartments near me are around 1000-1100 sqft.
> An 800sqft apartment is larger than any apartment I've rented.
Not sure what kind of apartment you're renting... (or maybe you're out of touch with the market?) 500sqft is a studio and you're not fitting much more than a bed and desk in there. You have to remember that square footage includes things like bathroom, closet, washer/dryer if they're in unit, etc. And that realtors exaggerate so in practice an apartment advertised as 500 sqft is more like 350.
Please just take a look at Zillow/Redfin for one moment and tell me where you see 500sqft condos that look like actual condos rather than studios.
Austin and Atlanta have smaller population densities compared to SF. SF is double Austin.
An 800sqft apartment is larger than any apartment I've rented. New condos can have 500sqft and still go for 800k in dense cities.