To be fair, most of what you're talking about can be achieved without the use of a physical device. The features are useful, the "SIM card" is not.
But your first example isn't like that: the SIM card, in essence, is a form of two-factor authentication. And it's really useful that way. Unfortunately it's a pity that it can only be used by the carriers...
But your first example isn't like that: the SIM card, in essence, is a form of two-factor authentication. And it's really useful that way. Unfortunately it's a pity that it can only be used by the carriers...