I'm not convinced that banning the bags was made for environmental reasons at all. I suspect supermarkets see it as a cost saver.

I bought special bags a few months ago. They have dowling or some such thing in the handles, so they can hang open in the trolley. When not in use, they roll up  and can hang on the hook near the handle of the trolley. So when I get to the checkout, i unload the groceries, then unfurl the bags and I can pack the groceries as they are scanned. This is in Aldi's i have to point out.

I think their set up is probably going to be the most efficient. Asking check out people to handle used bags might become a bit of an issue down the line for health reasons.

I read a woolies ad where they said once one of their bags wears out they will replace it for free & i think that sounds like a fairer solution. Then if a checkout operator struck a dirty bag, they could whip out a new one instead. The only trouble with them is they are long so a bit awkward to carry around if you want to browse other shops first. And I have learnt from experience to use the bigger bags only for light things or they get too heavy to lift.

.