[retrac]

The inconvenience of "my piles of money will no longer be legal tender in five years" and "all of my money is locked in accounts I cannot access starting immediately" are in entirely different categories.

I experienced this directly, when the electronic payment system recently collapsed in my part of Canada for ~2 days. I fortunately had a small amount of cash on me. Without it, I would have been unable to buy lunch, top-up my nearly expired phone plan, and then buy a train ticket and go about my normal day. It was also fortunate for my friend, who I lent $20. Can't take cash out at the ATM either obviously. I would have been stuck at home all day. I wouldn't have been able to give a small amount of money to my friend. Being able to lock people out of their bank accounts is far more specific, and disabling, than regulations on cash could be.