EV, you're partly correct.

My phone service - when I had it - was over 50's period wiring. This wiring is still in place.

Alas, I have gone 'all cell phone' now.

My computer uses the cable company's coax (RG 6); they're continually trying to get me to use them for phone service too.

Also, perhaps relevant to the code requirement, in my home the 'service point' for the phone is on the opposite side of the house from the electrical.