The state of the art for self-serve is low right now; it's like comparing a servant to a hand-cranked washing machine (current coffee vending machine experience). But if you compare to modern models that go quietly to work and have affordances like locking/unlocking on touch and projecting green or red dots on the floor to let you know if they're done washing, preferences will change.

Currently, companies that make people self-serve with touchscreens in restaurants or grocery stores are most commonly giving them a hostile (even hateful) user experience. But as voice UI starts to be more common, and you can marry visual and voice ...