A while ago in the Guest House, Southport, a group of young people whom I hadn't seen before ordered a large round of drinks and offered to pay with a card. "We don't take cards," the barman replied. This resulted in a scramble to get the necessary cash together. At the time, I thought it odd that they assumed that all pubs take cards, but if where they normally drink does, perhaps it's not so surprising after all.
The Guest House did try taking cards for a while, but abandoned the experiment. I don't think there were many takers, and there are costs involved for businesses that accept them. As it's a drink-led pub, perhaps the charges ate too much into the margins. I might out of interest ask the licensee why she stopped to see whether my guess is correct.
The only time I've used a card just to buy drinks was during that short-lived Guest House experiment; I just did it for the novelty, and was slightly taken aback paying for my evening's drinking in one go. I prefer to see my cash dwindle in dribs and drabs as the evening goes on. Besides, there is a hole-in-the-wall about two minutes' walk from the pub. I sometimes use a card in a pub if I'm buying meals with my drink, but that's it: beer on its own is part of the cash economy as far as I'm concerned.
Pubs that don't take cards must be among the few businesses that operate solely on a cash basis nowadays. There is a corner shop I know that has a 'cash only' sign on the door, and perhaps there are small newsagents that are cash only, but in the world of business as a whole, such a way of operating must be uncommon. I wonder whether such pubs will ever join the cash-free economy. If they do, I'm sure I'll adapt, but in the meantime. I prefer to pay cash for my beer.