I think it's important for there to be options - if you are reliant on the payment network, what happens if it goes down? What if someone for whatever reason is

I think it's important for there to be options - if you are reliant on the payment network, what happens if it goes down? What if someone for whatever reason is unable to use their card? Having cash as a universally accepted backup is a good thing. That being said, I can see all the issues with the implementation - I've experienced some of them myself. But, why have we not seen any improvements? We already have mechanisms for processing cash and change automatically, vending machines do it all the time. Self-checkouts seem to manage cash just fine. Just a speculative idea, but why not an automatic cash processing machine on the side of the main line? Tell it what the amount owed is, person can move over there and take all the time they want digging through wallets without disrupting the main flow. Possible issues with employees having to take time out for fixing issues with the machine, but then you have that problem with card processing machines anyways. Some Walmarts have both cash/card machines and card only machines - seems like a reasonable compromise. There are clear benefits to being able to process both card and cash - why are we so fixated on getting rid of cash instead of bringing the process to the same level as card?