Comment by dredmorbius

Doctors' offices, hospitals, and schools are well aware of this problem because they're dealing with both the outgoing and incoming elements of it. Many hospitals no longer permit direct calls to inpatient rooms because of the spam and fraud rates. Outbound communications are similarly frustrated, and are driving use of online and app-based contact methods (with ... their own issues).

Other organisations, institutions, and businesses too. HN discussion tends to focus on the consumer side of this, it's what most commenters have most familiarity with themselves, but you'd better believe that pretty much the entire phone customer base is fed up to there on this. Which puts the entire network at risk of defection, a risk that telcos have been talking publicly about for over a decade now:

[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://mastodon.social/@BroadbandBreakfast/1169990755811584...>.