I get a lot of them, and being a real estate agent I sometimes get calls from potential clients whose numbers I may not recognize. But I've discovered that when I pick up if I don't say anything for about five seconds the robocall will beep-beep-beep and move on, while if there's a person there they will usually say something after three or four seconds of silence.
I one time got a robocall from a spoofed number. The number I recognized as one of my refinery clients.
If it’s a number I don’t recognize, I don’t answer it.
If it’s important, they’ll leave a message.