Like it or not packaging does serve a purpose. If it was only fed back into the waste stream it could be recycled, but lazy people are lazy. In your example above if you forget your own bottle you buy another anyway, so who would win? The retailer
You already buy a bottle that will last thousands of years anyway.
Bring your own paper bag to the dispenser and fill it with crisps or biscuits or cornflakes or flour? Nah.
Tupperware, it’s going to blow your mind. If you’re quick you could travel back in time and sell it in peoples homes at parties.
It doesn’t though, does it. That might work for drinks, ignoring the abuse the system would get (free refills! Yay!)
No more open to abuse than the current ‘system’ and shoplifting.