Robotic waiter is easy and already implemented, just look at conveyor belt sushi or iPad ordering.

I meant robotic pipeline that starts at electronic ordering, mostly robotic cooking, and delivery by free-driving delivery robot on the restaurant floor.

OK, makes some sense. Though getting a free-driving delivery robot instead of a conveyor belt sounds a bit like using humanoid robot to wash dishes instead of a dishwasher.

Free-driving delivery robot makes sense when the restaurant has "classic" seating, including with no adjacent walls, and portion sizes that would make conveyor belt quite wide

Maybe. Though this reminds me of people trying to design a horseless carriage:

It's totally doable with modern technology, but in all honesty, modern cars work better.

(Off-topic: now that I think about it, it would be fun to see a 'self-driving carriage'. Ie you keep the horses, but replace the coachman with technology.)

FWIW, conveyor (or just any other static logistical mover) vs independently driving robots (or even crewed systems) is a valid spectrum that you apply in both internal factory logistics (from workers driving, through automatic robots, to conveyors and internal trains) and nation-wide systems (lorry vs. train, pretty much)

Yes, it's a valid spectrum. Definitely!

About your other example: I would expect self-driving lorries in a few decades to look very different from current human-driven lorries.