Ya, it reminds me of that Whack A Mole game. Every time legislators enact some new rule or regulation, the robo people just find another way around. We got rid of our home phone because of them. Now my "SmartPhone" tells me when its a spam call most of the time, but unless I recognize the number, I don't answer my cell phone either. If I know them, they will leave a message and I can call them back.
My cell phone tells me when it's spam too. Otherwise, I treat every call the same as you. If I don't know the number or caller, I don't answer it. If it's someone I know, they'll leave a message.