Yeah cash isn't cost free, but neither is card. Cash can save money when you pay suppliers etc with it too, so you aren't cashing it all.
It's more about who has control over the economy for me. It gives banks and govts unbelievable power in the future to exert control and cash is absolutely essential in that respect esp as I say to more marginalised groups.
I reckon I save £100 a month since purposely using cash more, although that is probably through just being more disciplined. It's never a hassle. Pop to the cash point near me and get £150 or so and it takes 30 seconds.
There has to be place for both and like I said, businesses that don't offer that really can't claim to be inclusive