what's your ebay username Imps?Me being a far rightie alt-right and obvious climate denier does the same. The "charidee bags" which come through my door almost daily are used as bin liners, and I always have a bag in my pocket to use if I go shopping. If we do a planned shop then we take more. Being honest I have always taken "my own*" bags to the shops because the ones they were giving out were crap.
*of course they aren't really my own because they came from other shops but I mean the ones that are a better quality than the flimsy ones the supermarket were giving out towards the end of the "free bag" era.
On your last point I don't leave any bags out for charity. I put my charity things in the charity bins at the fire station. Clothes, Shoes, Toys. Unless it is designer and then I stick it on ebay for someone else to use.