We humans, and the businesses we create, are creatures of habit. The physical SIM card is one example. There was a time (and reason) when they were needed. But their usage is now due to it just being the way it’s always been done. In 2022 it is now low hanging fruit, technically speaking. It’s just getting the carriers to adopt it (understandably this brings carriers an upfront adoption cost but long run it’s a money saver).