[SamWhited]

This may be different per city, but at least near me this isn't true, the suburbs have a grocery (or several).

> Presumably if you pick one, you'll start to see the same faces, though

Sure, and you'll likely only see them in the grocery and not elsewhere. Probably the same with the bar; I too know a bunch of regulars at a local bar, but likely not going to run into them outside that bar unless we become friends and make specific plans to do so. Also those people probably aren't my actual neighbors. It's a different kind and frequency of chance meeting when the built-environment is designed to facilitate community. I'm not saying that you'll literally never meet a neighbor in the grocery, it will happen, it's just not going to happen with the same kind of frequency as if we actually designed the built-environment to encourage it.