What would be nice is a service that just forwards unknown calls to someone competent.
Or just blocks them?
Because I'd like to think I'm 'someone competent', and on my own phone I only accept (non-personal) calls that I'm expecting, or can see a reason for.
Maybe this is a new angle for Google Voice or similar services. Protect vulnerable members of your family with a fail-safe auto-attendant system with approval rules.
It's not fully automatic and I'm sure scammers will come up with new scripts to still trick people into answering.
Over time it should allow Google to flag numbers as potentially being a scam, marketing, etc based on other users flagging a caller. Saves Googling for that information which is what I currently do with an unknown number. The only risk is spoofing/false positives putting your number on some blacklist.
That was the other thing. It was impossible to get my grandparents to do this. I think I eventually got them to let the answering machine answer and not return calls for messages from anyone they didn't recognize.