Earlier quoted context omitted.
I support more density, but the relationship between density and personal space isn't side-stepped by building up. You're just adding a vertical commute component. It's better than yards and boulevards, but a building of three-bedroom apartments to the edge of space will have a different human dynamic from one with mostly one-bedrooms.
Well first, a 1-bedroom is the most expensive way to live, at the rate we're going we'll have 3-bedroom apartments with 3 families per bedroom instead of 3 bedrooms per family :). Back to the Industrial Revolution tenements. You can get your human dynamic just fine on sidewalks, cafes, parks, etc. It doesn't need to be in-building. And even ~70 stories by elevator is still only a few minutes, nothing like the hour-pl…
More density means fewer [EDIT: more] people within walking distance of each café, park and restaurant. That, in turn, affects how many of them there are and how eclectic they can be.
Density is people over space. If you give each person more space, you reduce density. This can't be avoided.
> nothing like the hour-plus train rides middle-class people in cities currently need to endure
They don't need to endure it. Stamford, CT and Rochester or Port Jefferson, NY are nice cities with middling densities.
But many people don't want that. They want restaurants and nightclubs and parks with rotating art installations that only emerge and make sense when you pack people together.
Sure, you can put one or two large units in the mix without screwing things up. But not a lot, not for everyone. Else you end up with urban deserts.