[gwbas1c]

Ever see a soda or beer can? Pretty standardized. Same goes for a beer bottle, or even a lot of soda bottles. (This is my perspective in the US, but things seemed similar the week I spent in Europe and the week I spent in India.)

1 gallon milk jugs are quite standard, same goes for milk cartons.

When I was a teenager I worked in a dairy. We sold milk in both single-use containers and returnable glass bottles. The returned bottles were washed and refilled. The "problem" is that single-use won in the marketplace. The owners couldn't get it together to charge a deposit on the glass, and lost a lot of money from customers who didn't realize they had to return the glass bottle. (Edit: All of the containers, single-use and returnable, were standard and came from a distributor.)

We really only see unique packaging when some business sees it as in their best interests to design unique packaging for their product. Otherwise, beverage / food makers are just going to buy easy-to-get equipment that fills easy-to-get containers.