I dont carry cash because it isnt convenient. First I dont like when my pockets are full with coins. They are heavy, they damage clothes and wallet. Secondly purchasing can be tricky; people can have no change, the price can turn higher than if you pay by card. For example you need to pay $17,50. With card you would have paid exact amount. With cash seller can have no change and you would pay $20. Or you will put $2.50 in a jar at home, leave in the car, leave as a tip, making the price also be $20 in the end.
Can a country survive without cash? I would say instead that some cities can survive without cash, some not. Large cities can exist easily with digital payment system. In small town, where it is still usual to visit markets, to buy directly from producer it will be harder.
My experience. I pay by phone or by watch. I order food products online and get them delivered. More often I do same with clothes or other items. There are not markets nearby, no small individual sellers. A lot of payments for services I can do with mobile app.