[potatolicious]

McDonald's does automate their production processes to a large extent - the fries machine requires very little human oversight apart from taking it out when done.

The trouble with robotics is that it's expensive and time consuming to scale, and deals poorly with variance, at least for now.

If your McDonald's is a smash hit and you're experiencing much higher than expected traffic, you can scale horizontally by quickly hiring more workers. All of the tricky bits of producing the product (e.g., correct portioning, correct frying, correct cooking) are already automated, so this labor force is easy to bring up to speed.

Compare with a robotic McDonald's, where you'd freak out, order a new burger-maker-matic from your vendor, and wait 6 months for it to arrive.

Or perhaps worse, you have a maximum capacity of 1000 burger/hour, scaled for your lunch-time rush, and those machines are idling the rest of the time. In a normal human environment you just bring in fewer people during the off hours - but with a robotic work force you are always scaled for peak demand. In businesses that are periodically peak-y this is incredibly inefficient.