Have you ever been one of those people aghast that a shop won't take 'legal tender'? That's not what legal tender means, but now you can be right in practice even if getting there the wrong way.
Ever lost your card or whole wallet somewhere and been glad that having cash meant you could still buy something?
Concerned about privacy? Concerned about security of payments when there's an issue with your bank?
Have a bit of sympathy for people who prefer to pay in cash for whatever reason even if you yourself prefer card or waving your phone?
Sign this petition to require businesses and public services to accept payment in cash: https://petition.parliament.uk/petitions/700404
Poland has such a law, with some exceptions. So can we!