In Denmark, you're forced to use the state-run "NemID" for credit card payments, making for some weird situations where you authenticate with NemID inside iframes on shady URLs.
The same NemID is also used to file your taxes, look at all your health info, get married, everything basically.
Credit card payments are much lower security level, and they're basically forcing sharing credentials amongst all the sites you pay on.
2FA is already mandatory by the PSD2 directive of the EU. I use my debit card as the second factor to access my bank account here in Germany via ChipTAN