That sounds like a pretty miserable user experience though. People are forgetful and lose things. Doing something online for the ease of it only to have to wait

That sounds like a pretty miserable user experience though. People are forgetful and lose things. Doing something online for the ease of it only to have to wait for something physical seems like a big step backwards as far as UX is concerned. Until you make good security dead simple it'll never be used by the majority.