You might be right for people who have ordered a dominos pizza many times and already know exactly what they want. Rattling off your requests to a person might be faster and less stressful than navigating a UI.
But what if you don't know what your options are and how much they cost? You have to ask the person to list off the possible pizza styles, sizes, toppings, and the prices for each one. Then they have to tell you about all the available side dishes and desserts (with prices, again) and how there's a half-off deal if you get THIS side with THAT pizza on a Tuesday, and on and on and on. It'd probably take a good 20 minutes to convey all that over the phone (I hope you have a good memory or are taking notes), and by the time they're done, the poor employee is probably so frustrated that they're ready to strangle you.
Or, I can suck up all that information at a glance on dominos.com, and I won't have to repeat my credit card number over the phone 5 times before they get it right.
Restaurant websites always, without exception, suck. Dominos, while the pizza is garbage, has a wonderful ordering website. But even then the actual menu is awful.
They are always a sales funnel first, menu second. They cannot give accurate ETA, ever. It’s harder to display multiple choices well on a screen vs a sheet of paper.
Unless you are a place with 5 menu items, the paper menu is superior in almost every scenario.
Well, restaurants (simple or fancy) provide an excellent analog counterexample: there's basically always a menu that you look at and select items from - the definition of a graphical user interface.
Conversing with a person tends to be more intuitive than using a machine, but also more ambiguous and sometimes more difficult to get clear information. If I already have all the information I need, or if I want an opinion instead of objective fact, then going through a person can be better.
Otherwise, they're just acting as a voice interface for a GUI that I'm perfectly able to navigate on my own, and I'm not a fan of voice interfaces when dealing with technical systems.
