The situation is very different here. Our city government is going to take up the issue of shops that no longer accept cash and now only accept cards. Refusing to accept cash is being called discrimination against poor people who do not have cards.We were given to understand that other cities have taken up this issue, too. We are told that there is a population of poor people who do not even have bank accounts.
I think it is illegal here not to accept cash (legal tender) but my sister was telling me about a large shop in Sydney where you had to go to a special counter down the back if you had cash as the registers in the main shop only took cards. There are no passbooks for new accounts now but my sister use to have to take an elderly cousin's passbook in and have it updated every month or so. My cousin would not accept anything else. It was a bit of a hassle. I think poor people here have to have bank accounts as I do not think they could receive any government payments without one. My last night in Vancouver in 2017, I paid cash for my dinner (I wanted to get rid of Canadian money) and the middle aged waitress said to me "Oh cash, no-one uses cash anymore" Again back in January 1977 I caught the train from Venice to Innsbruck. It was delayed by snow blocking the pass. I got rid of all my Lira before leaving Italy as you did in those days. I checked into a B&B in Innsbruck but the lady could not cash my travellers cheque until her husband came home. I had not had any lunch and walked around the town for an hour or so looking longingly at restaurants. Finally went back to the B&B and the husband cashed my cheque and I had a lovely big Wiener Schnitzel. Been a favourite meal ever since. How much easier travel is now, not only the Euro in most countries but ATMs everywhere.
It's regarded a problem here too, that some stores don't accept cash. Poverty isn't discussed as a reason, but there are other reasons some people don't have cards. They can be here illegally e.g., or old people who've never gotten used to cards and hang on to cash.
I've actually had the opposite happen. I've gone to places where there are signs saying they don't accept credit cards, and to pay with cash. They all had an ATM in the business, so you could withdrawal cash and pay your bill.Thankfully, I always carry cash in my pockets.
I don't know if it's still true, but I believe at one time businesses had to pay the credit card company for the "privilege" of accepting the company's cards, so a business, especially a small one, saved money by accepting only cash.
Banks take a commission from the business when their card is used. American Express apparently charge a higher commission which is why you see signs saying their cards are not accepted. Banks here have guaranteed Paywave as, not needing a PIN (signatures are now only accepted if you are a tourist), they may be used before the owner realises their card is missing. Therefore the bank charges the business a higher commission. For that reason there is often a notice saying Paywave not permitted.
To my knowledge, the banks still take a commission. Sometimes you will go into a place and see a sign that charge cards are not accepted for purchases of under $5.00 or $10.00. That's because those business don't want to pay the commission on those small purchases, and will try to force customers to pay cash for them instead. Card companies have told business that they can't do that, but they still do it anyway.