I'm usually not one to focus on technological solutions given sociological problems, but this one seems to be a good exception. If we "just wanted to" [1] all this fake calls could be stopped by requiring strong authentication/authorization. We are very much used to just anybody being able to call my number, but that doesn't need to be the case. At the very least, cold calls should be treated as skeptical in the UI as instant messengers like Signal treat first messages. Probably this isn't enough, though, as it wouldn't have prevented the cases described in the article. Cold calling someone should probably require the caller to be traceable to a real, government-ID-verified person [2]. Even if that person is being defrauded themselves ("get a thousand bucks by installing this app and clicking a few screens") is would destroy the economics of the attack, as it would make each call expensive again.

[1] Structural inertia is the killer here. It will certainly not happen until the problem is huge enough.

[2] Exceptions can of course apply to numbers that are meant to primarily be cold called, like doctors offices. The callee possibly have to be specially trained to withstand this kind of attacks.