Recently sold an item on FB Marketplace. The buyer was annoyed that I insisted they had to pay in cash (they offered me a bank transfer) as they said they didn't have cash or a bank card with them (I did tell them before they came to collect; the annoyance wasn't due to turning up and then finding out).
So ... got to wondering whether lots of people don't routinely carry cash or cards any more but just rely on using their phone.