The staff told me that this reduced waste of all the drip they’d through out at the end of each shift/day.
Comically though, the coffee the machine put out was so hot that they were double cupping every order. The lids didn’t fit as snug over a double cup, so nearly every one of my orders dribbled down the cup as I walked out. And of course I went from “wait right here I’ll have your order right up” to waiting 2+ minutes for my cup to be made.
I’m not judging if it makes sense for Starbucks or not — maybe someone did all this math already. It was just a funny example of the ripple effects that stem from a seemingly easy decision to reduce waste, make each cup fresh, which would seem like no brainers.