@realcaseyrollins it introduces other dependencies, i.e. possible failure modes. Remember that a conventional telephone doesn't even plug into the mains. If you switch to VoIP, you depend on not only the online telephony provider, but also your ISP, and also the power grid; if you have POTS you only depend on the telephony provider. In turn that makes it less useful as an emergency means of communication.
@khird Ah that's a good point
I was thinking merely of audio quality fidelity, which really sucks rn