I have had the same home number and cell phone number for over 20 years. Both will display the calling number, and if that number is in my memory the person's name will be displayed. Both phones are on the 'do not call' list (which has become something of a joke).
Over the past few years I have noticed that telemarketing calls are now 'spoofing' the displayed caller number, usually appearing to be a local area code and prefix. Difficult, perhaps impossible, to really know who is calling or from what number.
I have learned to never answer the phone unless I know who the caller is, and actually want to speak with that person. Unknown callers simply go to voice mail, and if the caller is legitimate I can respond pretty quickly. In my experience, for every legitimate call received I get a dozen or more BS calls. Recently even the spam callers are leaving voice mail, probably automated I suppose, but I have to spend a bit of time every day to go through those to make sure I haven't missed any calls that are important to me.
I can't think of any other way of dealing with this nonsense.
On a related topic, I have read articles about some of the call centers being operated within prisons, using inmates to take orders, credit card numbers, etc. Probably not a good idea to give any information.