The major issue I see regarding a cash-free society (which I am part of by living in Sweden) is that it puts a big burden on tourists who have to pay a huge amount of fees when using their own cards in a different currency. It is also a bit similar for expats who, under certain conditions, can't apply for a Swedish person number (think SSN) and thus get a fully activated bank account. No bank account? Good luck doing…
This is untrue. For tourists and Visa/MasterCard paying with a card is usually cheaper than withdrawing foreign cash at ATM. With ATM you are slapped with a foreign withdrawal fee and you usually get worse exchange rate.
In general, the hierarchy of fees is no-fee CC < regular CC < ATM withdrawal < exchange cash at destination < exchange cash somewhere else.