As others have mentioned on this thread, Pixel's call screener largely solves this problem. For me it's a godsend feature and prevents me from getting into a bad mood from answering multiple robo/spam-calls in a day. I seem to have a heavily recycled number (multiple owners before) - as a result, I seem to have been receiving more than one person's share of spam calls.
For those unfamiliar: you can use Pixel's call screener to accept calls from unknown numbers. The effect is, an automated voice from your end handles the call, all the while printing on the screen what it says. It also transcribes what the other end says (mostly correctly). So you can "see" how the call is going, on your screen - its like a chat unrolling in real time. If you are convinced the call is legit (after having read enough of it), there is an option for transferring the call to you/mic and then you can take over. It also has some canned prompts you can have the call-screener speak out (these options appear when the screening is in progress).
For those unfamiliar: you can use Pixel's call screener to accept calls from unknown numbers. The effect is, an automated voice from your end handles the call, all the while printing on the screen what it says. It also transcribes what the other end says (mostly correctly). So you can "see" how the call is going, on your screen - its like a chat unrolling in real time. If you are convinced the call is legit (after having read enough of it), there is an option for transferring the call to you/mic and then you can take over. It also has some canned prompts you can have the call-screener speak out (these options appear when the screening is in progress).
Very helpful!