I am not an economist, but in this world of negative interest-rates (now common in Europe), another reason for cashless is to prevent people from keeping cash at home, behavior that make sense when the bank is making you pay for having a positive account.
And as a cryptocurrency enthusiast, this cashless trend is also a way to make it harder to hide your crypto assets: hand-to-hand exchange of cash against crypto is indeed one of the best anonymization way.