The re-usable detergent bags are nice, and many countries do distribute milk in thin plastic bags that you then empty into a pitcher at home. But as parent poi

The re-usable detergent bags are nice, and many countries do distribute milk in thin plastic bags that you then empty into a pitcher at home. But as parent points out, exchanging glass bottles isn't really better for the environment (in terms of CO2) as compared to properly disposing of plastic. No real reason why those deposit+refill bottles need to be glass; they could just as well be quality plastic and reduce some transport-weight. Similarly having a guy driving a truck around to deliver heavy liquids seems inefficient when you could just as well bring all your plastic bottle back to the store at one time and refill from big tanks there.