The answer has been mentioned a few times, while everyone else but the USA is using a physical SIM card Apple cannot put anything here, because then they would have a US IPhone with some tech/battery etc and a worldwide iPhone without that tech/battery etc.
Next year I’d imagine it will be utilised as they will either go full esim or have to backtrack.
Next year I’d imagine it will be utilised as they will either go full esim or have to backtrack.