If you have the technical know-how to protect your private key, and you're immune from rubber hose attacks, and there's no mechanism for key recovery outside your control, I'd agree.
However, people.
And I'm not aware of any system suitable to replace SSN that can withstand rubber hose attacks. That's where law enforcement & the justice department will have to step in, as always.
https://arstechnica.com/tech-policy/2015/10/how-a-criminal-r...
If your card holds a private key and won’t sign anything without also being fed a correct PIN you’d need a proper exploit of the application on the card to defeat it.
Like - US for a very long while didn't use chip & PIN - but it was simple to deny the transactions and as a consumer you were somewhat well protected, despite lax security. But this generates large costs, and perversely, the cost/uncertainty affects the small businesses the most.
Yes, when I use 3DSecure for an online transaction, the bank shifts the burden of proof to me (a correctly-authorized 2-factor transaction cannot be simply challenged with a complaint at the bank, I have to prove that it wasn't me). Still, it's hard to argue that 2-factor for online transactions is consumer-unfriendly, even if the consumer loses the deniability