We need to fix spam calls, but once a short term solution is created, these robocall scripters write around them. I think the best solution is letting every user create their own IVR system. This way, robocall scripters won’t know how to make their system react to make your phone ring. The simplest example of this would be a randomized code the IVR system makes a caller enter before it will ring your phone.
This project has a long way to go, but if you like helping the code lives here.