Everything they can, at least. Still, someone has to load the fryers/grills, assemble the sandwiches (of which there are at least three different basic kinds, and many, many more variations, even some more then in some places), and wrap/package the result.

I don't forsee a machine handling the entire process anytime soon. There are too many edge cases.

(And I remember quite a bit of expletive-laden rage at the automation we did have when I worked there.. when it breaks, it's annoying. Fry dispenser not loading baskets, things getting stuck in the bun toaster and holding up the whole line, timer buttons on the holding cabinets failing so you can't tell what's been there for how long..)