I'm not part of the paranoid set, but I'm not as comfortable with the cashless society as many. I'm just not comfortable with the control and tracking that they afford to governments and corporations. Combine the cashless society with people who use things like Facebook, and I think you might as well just let the government and corporations insert a tracking chip into your body - they're being used in cars already. If you use an Android phone or watch, and something like Samsung Pay, you're pretty much already there. If you've ever wondered why you're getting certain types of ads in your inbox or mailbox at home, it's because your credit and spending profile is sold to marketers. And Facebook makes the bulk of its profits off of people who are willing subjects in its giant ant farm. But with that said, I only carry enough cash to cover an emergency situation and I use credit cards for probably 99% of the purchases that I make. I might write half a dozen checks a year, at most. I prefer credit cards because they can help track spending (yeah, for me and also anyone else who "watches" me), provide warranties on products and insurance on rental cars, offer cash back rewards or rebates, you get free use of the bank's money for 30 days or so (as long as you always pay the balance in full) and most of all, if you're a victim of I.D. theft or fraud, your liability is at most $50 in the U.S. - with most of my cards, it's $0. I never use debit cards and I never use an ATM for anything though. Most debit cards have little to no protection. And even if you're able to get your money back because of I.D. theft or fraud, it'll take weeks or months, at best. In the mean time, your money is unavailable to you. Other than people who are too undisciplined to manage a credit card, I've never understood why people use debit cards.
As far as things like cryptocurrencies, I understand the concept. But as their value/purchasing power is still typically pegged to the dollar, to me they just seem like something that hipsters like to use, in order to pretend that they're on the cutting edge of something. IMO, they're even sillier than people who hoard gold coins and bars in a home safe, thinking that if there's a zombie apocalypse or whatever, their gold will see them through. But now, if you're an international criminal, I can see how cryptocurrencies would be a great thing for you.