Comment by dredmorbius

Tell them to leave a message.

The problem runs the other direction as well. Friends in the US tell me that the local hospital no longer permits direct calls to rooms, on account of both robocalls and spams. It's now necessary to call through the operator.

This is a (slight) inconvenience to friends and family, and a considerable workload and staffing burden for the hospital.

I've been predicting the death of telephony, as in a universal direct-contact, single-directory (as in: everyone has an identifier which can be reached by any other party regardless of provider) for about a decade now. It's a death-by-a-thousand-cuts phenomenon, but increasingly it's difficult or impossible to reach specific individuals or organisations by phone. The issue isn't just landlines (used by a minority of households in many states, though some such as New York are apparently still above 50%, contrast < 20% throughout much of the central US), but all public switch telephone networks.

Expect a fragmentation to various online services (FB, WhatsApp, Google, Skype, Zoom), home-rolled networks, and those who just opt out fully.