In short because numbers take less space. In long It would require changes in IMSI. It’s probably possible with esim, possibly you could add euicc eid application as JohnSmith234@your.operator.email inside your esim profile but not sure if it would voilate some headers lenghts numbers so it won’t work everywhere except one operator and it’s relays.
In short because numbers take less space. In long It would require changes in IMSI. It’s probably possible with esim, possibly you could add euicc eid application as JohnSmith234@your.operator.email inside your esim profile but not sure if it would voilate some headers lenghts numbers so it won’t work everywhere except one operator and it’s relays.