A government run public service means:

1) The government now has a full purchase record of every purchase you make

2) There is not a competing infrastructure where you can distribute your transactions across multiple companies to avoid a full profile building up

3) The government now has an incentive to eliminate un-surveilled options like cash and checks.

4) The government is now required to consistently legislate every single "he said, she said" fraud situation. Since it requires publicly available and consistently followed guidelines, this means everyone knows exactly which sorts of fraud work well

5) The government can trivially ban payments to anyone they disapprove of (porn, bitcoin, Iranian refugee charities, anyone who has the wrong opinion on Israel, etc. etc.)

6) The government can also wield all of this as a cudgel to threaten bad actors - do what we want or else we propose you go the Non-Payment List, we reveal your porn receipts, etc..

7) I don't even want to know what this does to the complexity of trying to use a card when traveling internationally

> 7) I don't even want to know what this does to the complexity of trying to use a card when traveling internationally

Not much - Canada has debit/credit cards that use debit domestically and Visa or Mastercard internationally. They're the default type of debit card that many people get.

The government does that already. Only point 7 still stands.