Easy. Spammers. If there is no caller ID and I don't know you I don't answer the phone. No doubt I miss an important phone call from time to time. This is the uncounted cost of spam. I hate it. We put up with it for some reason.
The only people i know who wanna call me are the people at my psychiatrist's office. Anybody else trying to get ahold of me is probably spam not anyone I'd know in real life so there's no real point picking the phone up unless i'm expecting a call from my psych...
You can avoid spammers with this one weird trick: Have a phone number NOT in your home area code. I have an Ohio phone number but I live in South Florida. If it’s not a Florida area code calling then I don’t answer it.