1. And physical keys get lost all the time. So then you need to solve the "lost key problem", and proving identity then means you're often vulnerable to the same types of things that make sim jacking a problem in the first place (to be clear, though, I think the much bigger benefit of physical keys is their resistance to phishing, not their resistance to sim jacking).
2. Actual physical keys are expensive. The margins on many types of depository accounts are razor thin, and giving everyone a physical key would be significant.
3. So an option to #2 is then to use the physical key built into nearly all smartphones these days. But I can definitely say that, at present, that option still doesn't work that great. Have had loads of problems using a phone key with Google's Advanced Protection, many times bugs on Google's part. Also, this normally depends on bluetooth, which can have a ton of connection issues.
2. Actual physical keys are expensive. The margins on many types of depository accounts are razor thin, and giving everyone a physical key would be significant.
3. So an option to #2 is then to use the physical key built into nearly all smartphones these days. But I can definitely say that, at present, that option still doesn't work that great. Have had loads of problems using a phone key with Google's Advanced Protection, many times bugs on Google's part. Also, this normally depends on bluetooth, which can have a ton of connection issues.