If we’re in to do Orwellian things, I’m not sure what’s technically stoping us from doing it now. All bills are scanned at the banks, we can flag who got which lot from the ATM, major POS systems scan for counterfeit, and retailers will return to the bank any excess from what they need for day to day exchanges (or not bother and return everything to the bank to get new bills in packaged stacks).
We’re already trusting our govs for not abusing the situation. The bridge is already crossed in my mind, going pure cashless is a small step in comparison.
Many other are not completely there yet but move in the cashless direction steadily.
Israel is not a cashless society yet but already requires people to specifically declare cash savings exceeding certain (pretty humble) amounts even if they have already declared the income and paid the taxes.
Scare stories about authoritarian governments that still somehow respect rule of law and due process are funny.