> Walkable cities are too small to have the wealth of options a car (or transit) city does.

It's counter intuitive but it's quiet the opposite. I've lived in the UK for a while and in some pretty walkable cities. Even in the smaller cities, what you'd find is a wealth of different shops and options catering to all sorts of needs.

But then just consider that when you are walking you are being exposed to all the shops in the city.

Cars isolate. You are much less likely to notice the hole in the wall specialty shop and you are much more likely to instead just go to a Walmart or national brand place to get what you want. And you'll much more likely want to stop at all in one stores such as Walmart because you don't want to hop in your car multiple times to get the shopping done. In walkable cities, it's almost like a mall experience in every city center. 3 doors down is the hardware store and 2 more stores is the candy shop.

And because that downtown location is a highly desirable place with lots of foot traffic, any shop that goes out of business gets quickly replaced with another. Which means you generally end up with a lot of pretty high quality stores.