Earlier quoted context omitted.
Given caller ID spoofing, they really shouldn't even accept calls from numbers they do recognize... especially with tech like this. Let it go to voice mail then return the call afterwards.
So what's the end game there - using voicemail as a poor man's texting?
https://news.ycombinator.com/item?id=21494300
[S]ince mid-2015, a consortium of engineers from phone carriers and others in the telecom industry have worked on a way to [stop call-spoofing], worried that spam phone calls could eventually endanger the whole system. “We’re getting to the point where nobody trusts the phone network,” says Jim McEachern, principal technologist at the Alliance for Telecommunications Industry Solutions (ATIS.) “When they stop trusting the phone network, they stop using it.”
https://nymag.com/intelligencer/2018/05/how-to-stop-spam-rob...
At the point at which individuals and businesses in sufficient numbers find the downsides of participating in the PSTN exceed the benefits, they'll start defecting to other systems. Likely small and closed networks initially.
It took decades for the telephone to become established as the principle means of business communication, and as it was, numerous other alternatives existed in parallel: postal mail, telegraph, telex (for what we'd now call b2b communications), fax, and early email systems.
Email seems to be dying along with telephony, and for much the same reasons.
It's occurred to me that much the value in social networks is in trying to corner a sufficiently large directory (that is, user base) to be able to credibly take on telephony. What seems to happen is that as these networks grow in size, they too fall prey to the hygiene factors already affecting telephone and email comms: spam and annoyance messages, with concommitant trust issues in the network as a whole.
Whether a technical solution to the trust and identity problem can emerge (and preserve privacy and protect against the surveillance state, surveillance capitalism, and surveillance by other actors (organised crime, racist or facist oppressors, stalkers, etc), remains to be seen. I'm starting to think that's a hard, possibly an impossible, problem. An essay of Herbert Simon's I've recently turned up is exceptionally discouraging owing to a critical error Simon made in it (claiming Nazi Germany committed it atrocities without the benefit of mechanical data processing -- it in fact had ample assistance willingly provided by IBM).
More generally, I'm suspecting that progress in information technology and communications capabilities reduce trust relationships, with some fairly strong historical evidence.
(Overall risks may be reduced, but the mechanisms by which this occurs replaces actual trust with validation, verification, and surveillance mechanisms).