I have a work phone and a personal phone. The work phone i answer calls from I known numbers all the time. My contact information gets passed around as part of my business. For a while I had scammers hitting my number 3-4 times per day. I answered and fucked with them every time. A little free stress relief through the day. Now I almost never get them anymore.

My personal phone I have always screened all the calls. It still gets hit with scammers 2-3 times per week.

I guess you are right. There is a list going around of numbers who waste their time.