Yes, that is how employment works, and the compensation is better than livable for those who would make that elsewhere.
After you are a toddler, and once you are rich, do you need permission to buy snacks?
If work has shitty coffee I can of course bring my own but the kind of people that buy shitty coffee are often stingy in other ways that are more meaningful like raises. It might well be a good indication to look elsewhere.
Or is it even a problem? Maybe Amazon deliberately puts on their best Ebenezer Scrooge to weed out people with too much taste and not enough nose-to-grindstone.
You guys clearly think more about what messages the workplace is sending you than maybe Amazon wants their employees to. ;- )