The reality in the Nordics is already that most people never use cash.
I cannot recall making a cash transaction in the past 18 months.
It's mostly older people using cash anymore.
For example, if you start having kids, and going into their sporting events or whatever, you'll find that any form of electronic payment is most likely not accepted in the pop-up cafeterias ran by parents. No cash? No coffee for you.
Cash is still a handy way to give your kid some money to spend. I know some people already get their second graders a debit card with a monthly allowance, though.
But yes, about 99.5% of the transaction volume in my household is electronic.
The primary use of cash is shopping in Christiania.