Where does a line cook's use case fit in it? From what I know, uber eats sends a order to a restaurant, an employee manually punches in the order on their POS system, and the order ticket goes into the kitchen

You don't think there are a variety of people at a restaurant who might interact with the system? Is this particular detail so very important to the point of the parent comment?

I think the parent comment tried to prove a point by making an extremely frivolous claim and naming every person they could think of as a “user” which means they are either wrong or they failed to adequately make whatever point they were trying to. Uber doesn’t need an api for line cooks, so using them as a justification for a large number or micro services was not rhetorically sound.