Comment by Nifty3929

4 hours ago

How would I connect to my own network? Wifi and cellular solve different problems.

That's purely a software problem that stems from typical usecase. There's no technical reason preventing phone users from selecting the network to connect to. It's just that currently a SIM serves that purpose.

On layer 2? I guess that would require a virtual network. For layer 3 and above, everything has an IP address so use that?