> Even if you find a job and a place to live in the same superblock, people are gonna (a) want to have options to leave that job in the future and (b) know people outside of those blocks.
You seem to be stretching really hard here to try and conflate "no driving through them middle of the superblock" and "people in the superblock aren't allowed to have cars", but those aren't the same thing at all. You just put the parking in centralized places at the edge of the superblock, where economy of scale can apply.
If everyone still needs cars, you gotta put them somewhere. And the roads have to be big enough to accomodate the commuting and the inter-block traffic. If you put them on the perimeter and route the cars around the perimeter, you don't have a walkable city, you have a car-centric city of high-traffic roads people drive on to walk around little walkable islands. *Same even if you put them under the superblock.* Tons of these sorts of mini-downtown walkable areas in LA, for instance, but nobody's calling LA walkable.
Transit, transit, transit. You can't superblock your way around the need for it. "Walking to a car to drive to another part of town" instead of "Walking to a train to get to another part of town" is going to give you a dramatically different experience, since one of those is far, far more friendly to low-density SFH surrounding development than the other.
You seem to be stretching really hard here to try and conflate "no driving through them middle of the superblock" and "people in the superblock aren't allowed to have cars", but those aren't the same thing at all. You just put the parking in centralized places at the edge of the superblock, where economy of scale can apply.