Yes and no. I absolutely get where you're coming from; I'm an extreme introvert living in London, and the anonymity is about the only thing that makes it bearable. The flip side here, and in many (but not all) metropoles, is the near-impossibility of finding quiet, either at work (expensive commercial property pushing employers toward open-plan bedlam hell) or at home (expensive residential property pushing people into tiny thin-walled apartments).

I think the small-talk-with-everyone-you-meet thing is a characteristic of very small towns and villages. I've lived in medium-sized places that didn't have it. The introvert ideal of a blissful hermitage miles from anywhere is probably impractical, for many reasons, but I still have some faint hope of finding a liveable middle ground someday.

Modern buildings in London seem to have got the soundproofing right; of course you'll pay for it but it's worth it IMO. I live in a shared ownership (housing association owns 75%, me 25%) flat and it's completely quiet (the tradeoff is that I'm living in Tottenham as that's the only way to make it even vaguely affordable).

Sounds nice. I'm a bit further in (N4) and in an older conversion, and it's not even a tiny bit quiet.