The problem with your comparison is that you have it backwards. And airplane has many many more parts than a car so that scale follows. A cup of coffee, even a cup of Starbucks coffee, doesn’t have as many parts as a hamburger (and fries, drink, maybe desert). Starbucks has built in efficiency, but it’s not like a McDs. McDs is structured to 45 second in house and 60 second drive thru experience, from “hello” to “come back soon”, getting your order, filling your order, getting your money, bang bang bang. Starbucks can’t even get your order that fast. Because they don’t want to, Starbucks wants to be a place where you feel special and wanted and comfortable. They want you to do that as quickly as they can manage it because that’s where the profit is.
When McDs is in full cycle a dozen people could be part of your order process, one person is talking to you, one person is getting the food part of your order, another is getting the drinks, there’s the person keeping the bin full, there’s a person just making fries, 2 people are running the reg grill (where the little burgers and bigmacs are), 2 people are on the 1/4 grill (quarter pounders), another is running the fried food section, still another (or 2) in the “none of the above” area for grilled chicken and other oddities, then there’s a couple of runners bringing supplies from the walk-ins and storage. And that’s a mid-volume store with only one of each prep zone. It’s a machine, an assembly line, a real, actual, stole ideas from Ford assembly line. Starbucks actually goes out of their way to avoid that kind of assembly line, they want to be efficient but they want you to feel like an individual with an individual order. McDs wallows in mass production, Starbucks pretends nobody has ever ordered a coffee quite like this before.
The Starbucks I’ve seen have got someone taking orders and collecting payment, someone else steaming milk by the gallon, someone else cranking out espresso as fast as they can, and someone else putting it all together and adding the carmel/whatever else.
An assembly line.
The only personalization is at the end when they put the drink up on the counter and yell out “Triple venti carmel chai macchiato with a double-shot for Bill” (or whatever). I find the whole operation silly.
And I’ll no more tip them for that than I tip the kid who takes my burger order.