Of course I don't answer the landline if I don't know who's calling... that's like advising someone to not  stand out in the middle of the golf course with a metal umbrella in a lightning storm. I have a cell phone on which most all of my contacts call me and I never get scammers on my crll. I do not wish to be bothered by the landline ringing even if it is a call that I know not to answer. And has everyone has seeded here blocking numbers it is a lesson in futility because there are apparently up to about a quarter of a million different numbers being spoofed at any one time.  So on my landline I shut off the ringtone on both the handsets and the base unit. Friends and family or whomever can still leave a message and I can hear the message being recited, and I pick up the phone if I want to talk. If I miss that message my phone has the option of making a periodic beep to let me know I have a message waiting, but even that can be shut off if it bothers me.