I don't know what places you're talking about. Everywhere I've seen they use an espresso machine which isn't a case of 'push a button, right amount of coffee pours into cup', even places like Costa.
Even when they use en espresso machine (because perhaps you ordered an espresso), it makes no difference to the final product if that is automated entirely. A standard espresso machine requires a human only because it cannot automatically reload coffee.
The simple fact is that at this point humans are really only there for the 'experience', not to create the final product.
(I can see you editing your comment out from underneath me by the way.)
Humans in Costa don't add any value to your cup.
They might make you feel better, though, so we'll see if people are fine with being served by a robot (as I already wrote).
But, please keep focusing on the literal.
When pointing at the Moon...
> In most of those chain coffee shops what you get is a coffee vending machine with a human arm to move the cup.
What I'm adding is that anyone with eyes can go to a chain coffee shop and see that they aren't using a vending machine.
Employees do no more than employees at say, McDonald's. In fact probably less. Push a button, right amount of coffee pours into cup. Move cup. Push button, right amount of milk pours into cup. Move cup.
Replacing people by robots will make no difference to the final product.
What we need to wait and see is whether consumers want to be served by a human or whether they don't care. We'll have an answer very soon because for fast food and coffee shops there's just a couple of years before humans become operationally optional.
Personally, in a high end place where staff adds value I will care, but I couldn't care less in a Costa Coffee or McDonald's.