It’s also worth noting that transport does not have a zero cost on the environment. It’s why we did away with glass, it’s so heavy it actually becomes carbon intensive to transport. Especially when you account for greater spoilage percentages (due to the glass being mishandled and breaking more often than alternatives). The equation isn’t as simple as it would seem. The true solution is less likely single use drink containers of any kind and more likely some sort of reusable bottle you carry around with you and could fill up.