I'm not sure we really disagree, if I understand your response correctly. I _do_ think there can be improvement (and, probably, should).
My main objection was calling for using a device that is expensive, requires special/additional phone plans, and doesn't _really_ solve the problem (especially for most of the global population). I have a rather diverse set of friends by age, income and technical experience - and smartphones aren't the majority.
You are correct. I am not in disagreement with you. We definitely need a way to authenticate people. But like I said, authenticating systems need to be fool-proof enough to not allow false positives yet flexible enough to allow people to screw up and get a fresh start without wiping all their data. These two goals, by definition are the equivalent of trying to look towards the left and right at the same time.
My main objection was calling for using a device that is expensive, requires special/additional phone plans, and doesn't _really_ solve the problem (especially for most of the global population). I have a rather diverse set of friends by age, income and technical experience - and smartphones aren't the majority.