> Basically for the sizable transfers, there is relatively little faith in the user’s computers (including phones). To the extent there is faith, it has total liability on some capitalized party for fraud.

But that is expensive, so my impression is that for non-sizeable transfers, and beyond banking, for basically anything dealing with lots of regular people doing regular-people-sized operations, the default in the industry is to try and outsource as much liability onto end-users. So instead of treating user's computers as untrusted and make system secure on the back end, the trend is to treat them as trusted, and then deal with increased risk by a) legal means that make end-users liable in practice (keeping users uninformed about their rights helps), and b) technical means that make end-user devices less untrusted.

b) is how we end up with developer registries and remote attestation. And the sad thing is, it scales well - if device and OS vendors cooperate (like they do today), they can enable "endpoint security" for everyone who seeks to externalize liability.