>I've seen burger assembly robots that will make, from raw ingredients (including the ground meat) burgers in a handful of minutes.

Exactly this. A machine could make a far superior product in a fraction of the time for less money (at quantity). I worked at McDonalds through college, and I remember people (including myself) letting the pre-cooked hamburgers sit in the warming bins for hours passed the time they were supposed to. Gross! At a minimum, I can't see why everything in the prep-area wouldn't already be automated. I imagine there'd be far less waste as well with everything being stored in a pre-cooked temperature controlled manner until the customer orders it.

I wonder how long it would be before McDonalds followed suit if someone with the capital built a competing shop that automated to the max and made a superior product for a competitive price.