[numpad0]

What you have described is an “artist’s impression” diagram but not how it works IRL. Having physical SIM removes the requirement of the entire phone having to be a certified malware proof secure device, which is hard and a bit anti-consumer.

[usrusr]

Just imagine how nice things could be if physical SIM also doubled as a trust enclave for all your TFA etc needs that could be easily transferred to a new device, survive through OS reinstalls and so on.

[numpad0]

That was kind of tried with public transit/FeliCa but didn’t seem to work. For whatever reasons, even VISA is more comfortable with phone integrated secure element for payment, it seems. Maybe the way it is is less eggs in similar baskets.