Another small point...
Lets say you want to know what are the ingredients in an item.. or maybe you want to know what's good on the menu... how about you just want to ask why you got onion rings instead of fries...
In a big way the cashier was also supposed to communicate and befriend the customer. A smiling young face or a touch screen? What happens if one of the workers needs to go to the bathroom, opps sorry no cashier to go get those fries for ya.
What ingredients are in french fries? A burger? Only an idiot would have to ask.
Some people have allergies.
Do you know how many different types of oils there are for cooking?
Do you know how many different types of flour there are for buns?
What's in the meat, all beef, free-range, or corn fed...
Sometimes I ask whether the lettuce / tomatoes look good before asking for that... might ask if the jalapenos are pickled.
Tell George to put a couple of his spicy onion rings on that for me...
At the local BBQ joint I walk in .. they know me, the bubbly cashier tells me to say hello to my younger son, the cook played football with my older son, ... Why would I go to a McDonalds robo mart when I can go to a place with people I know and get fresh food served by humans.