They will have to still pay for it. If the RoI on these kind of campaigns become low enough, due to combination of higher cost and lower conversion, they will abandon it. You could develop a dialer app to autoroute, and perhaps even generate auto responses ( inverse robo call ?) to make it more frustrating

Yes, precisely. Does any research exist on what percentage of, say, cold calls, has to go bad before organizations abandon the practice? I'd google for this, but I'm not certain of what terms to use. It seems to me that percent honeypots might be relevant, percent of sabotage of cold calls, but I just don't know enough of this field to even start to get an answer.

I do know enough to say that a simple North American can cause enough ire in an Indian call center worker, that he will call back 4 times just to say "Fuck you, sir!", and that if, by chance, the same North American call center worker gets you twice in a day, the conversation is quite profane.