On the other hand, cash has its costs. You need to have a register, more training, more insurance, processing of cash at the bank, having it deposit cash at the end of every day, etc.
With credit cards you pay a fee, but you don't have to deal with all of those other things that people often don't consider.
If a significant amount of your business is cash based then the risk is much higher. If you're doing $100 worth of cash transactions per day then your registers and safe probably don't have much and you can probably get away with weekly or even monthly deposits. Whereas if you're dealing with $1000s in cash then you probably want to deposit daily, need a lot more security around your register and safe, and probably have a much higher quality safe too.
I've lived in Seattle for decades, and have -never- found a business that would not accept cash. If I -had- I would have set down my prospective purchase and walked out the door with a promise never to return.
Apart from a transit card (all the mass transit also takes cash ... no fee added), I'm not going to pay to feed the surveillance machine.
There have been a number of food trucks in the Seattle area that don't accept cash for the past 5 years. A popular food truck might have >$5k in cash sitting there by the end of the lunch rush - it puts an awfully tempting target on your back.
Where I live in Seattle, a lot of businesses simply don't handle cash at all, because break-ins for the cash register are quite expensive to deal with, and they circumvent that problem by simply posting outside the business that there is no cash.
One of the few businesses near me that must take cash, a dispensary, recently had an issue where somebody tried to break in using a stolen pickup truck to crash into the building. They didn't get the cash because they didn't get past the interior bollard system, but they did cause enough structural damage that the roof partially collapsed into the street.
I mean sure, US is special in this case, especially since you don't actually persecute small time thieves...
But i've paid with cash all over europe, and except for some vending machines, i've never been turned down, be it london, paris, berlin, belgrade or athens... from large supermarkets and museums, to local corner newsstands with a small fridge and cold drinks and local fast food joints. On the other hand, the most unsafe I ever felt as a traveller was in chicago, supposedly in a "nicer/safe area", and I've been through the balkans in the 1990s.
With credit cards you pay a fee, but you don't have to deal with all of those other things that people often don't consider.