Answering these calls generates more unwanted calls.  Recording the fact that the call was received is helpful and contributing to information, contrary to what you're saying, because it verifies that several people are receiving these calls and that they are more than likely scammers or telemarketers.  When I see nothing recorded, on a number, it is more frustrating because it make me feel as though I may have ignored a call from a legitimate individual, although I never answer calls I don't recognize.  Any information is better than none and recording the fact that an unsolicited call is received IS information.