W9-
The FCC's logic, and what you don't seem to consider, is those "two wires" are an interconnect system. A phone patch. The same way that a repeater, or a high seas radio station, patches a conventional radio into the conventional wired telephone switching system.
The fact that there is computer automation and signaling and a whole fancy commotion taking place to make this "normal" for cell phones, doesn't change the basic "phone patch" division of them.
I'm sure I'd read about cell phones (even GSM phones that are supposed to be running on encrypted networks once they hit the towers) being vulnerable to a "man in the middle" attack as far back as 2000 if not earlier. And even then, the supposition that governments liked this, i.e. so that stingrays and other devices could be used. (Remember, among others, it is the NSA's charter mandate to collect ALL electronic signals intelligence, and one can only hope they've done that effectively. Or not.)
At this point in time it is almost laughable to think about modifying the network. Millions? Of towers, cells, picocells, femtocells, phones, all relying on this system and unlikely to be "fixable". And a whole new (and incredibly localized) amount of 5G equipment being built and deployed very shortly. And all relying on those same vulnerabilities.
The same reason that the backbone of the telephone system (SS7, Switching System 7) is tolerated, even though it has been proven to allow any call to be traced from number to number, worldwide. (I think Mark Tobias has a video on YouTube about that one too.)