I'm poorly placed to describe it in detail, having only ever been an observer on a handful of occasions, but much of what you're describing exists today in not-

I'm poorly placed to describe it in detail, having only ever been an observer on a handful of occasions, but much of what you're describing exists today in not-even-particularly-fancy restaurants in Shanghai (and presumably elsewhere), enabled by QR codes and wechat voodoo. Think "scan code on menu to order/pay". It seemed like a very efficient system, and I'm sure you're right that the concept will take off outside China when someone builds a sufficiently it-just-werks solution (that hopefully isn't plugged into a massive method of social control). It's just too powerful of an idea space to go ignored forever.