Yeah, a lot of the issues with security on the phone (both spoken and text messages) seem to have to do with backwards compatibility. I mean they add layers on top of the old ones (e.g. to allow higher call quality) but somewhere you can still call someone using just dial tones.

I hope they're working on a new standard for telecom that allows unspoofable caller verification. That, and secure / verified e-mails. But that too is a standard challenged by 60 years of legacy (I had to do a quick wikipedia check).