I feel like this is a problem mainly unique to America. It's just way too expensive to open and operate a small retail business there any more, so the only ones that survive are those corporate chains mentioned above (cellphone stores etc.) and the high-end businesses you mention. You just don't see walk-in businesses in most places because they're not economically viable any more. Here in Tokyo, it's completely different: those tiny, independent businesses are everywhere. I'm not completely sure on why this is, but part of it is probably the car dependency (causing things like minimum parking rules), but even in places where the business can ignore parking requirements, it seems rent and labor costs are way too high. Part of this might be from the terrible healthcare system and skyrocketing housing costs. Whatever the reasons, over here it seems to be quite common for people to open small shops and run them by themselves, and that's not something I see in America any more.