So instead of reusing the free carrier bags people are now buying bin liners, nappy sacks, dog poop bags, feminine hygiene bags that truly can be used only once.
It's all very well using lifetime carrier bags but not so good when that fresh chicken or beef joint leaks. There is no way I would reuse that bag for shopping.
Meanwhile, the supermarket shelves are full of cucumbers, swede and cauliflowers wrapped in very thick plastic. The veg is prepacked in plastic bags (I'm looking at you, Aldi) and cans of beer are packed with extremely thick plastic rings to hold packs of 4 cans together.