Without going into great detail (as Im currently at work and just wanted to get this idea off my noodle) eSIM which is known as Embedded Subscriber Identity Module is now being seriously developed by some tech companies, for example Microsoft is pushing the idea of always connected PCs that utilize eSIMs.
Some of the backing partners for this technology is
ASUS, HP, Lenovo, Xiaomi, Dell, Huawei and VAIO
The eSIM would be woven into the silicon fabric of a devices modem.
Now my personal opinion is that once this becomes perfected it will allow for actual physical printing or minting of cryptocurrency thats still connected to the network/internet which would allow for sells/buys/trades.
Again, Personal Opinion and I will expand upon this later in the day once I get home and have time to do so.