I too have mostly stopped answering calls from numbers I don't recognize.
What I get are not spam calls, but silent calls. When I answer them there is no sound at all from the other end. If I let calls go to voice mail they leave long silent voicemails.
I also get calls which ring for only a couple of seconds, hardly long enough to reach for my phone before they hang up.
I've heard that these may be scammers trying to trick me into calling back, so they could charge me however many dollars per minute.
They might be attempting to get you to call back, but likely they're calling more numbers than they can actually connect. It increases the odds of getting answers on particular attempt, but they can also keep track of those that answered even if their talking robot can't service every connection. Now they know they've got a live number and will try you again.
Unless you are unfortunate enough to have a legacy home phone line, you should configure your (personal) phone to not ring for unknown numbers; maybe to let it ring if the same caller calls back twice in your succession.
New contacts can leave a message, and you can call back and add them to contact book if desired.
> trick me into calling back, so they could charge me however many dollars per minute.
Yup. Bitcoin scammers and dark-pattern website builders have got nothing on classic telecom scammers, exploiting fundamental flaws in the trust model.
What I get are not spam calls, but silent calls. When I answer them there is no sound at all from the other end. If I let calls go to voice mail they leave long silent voicemails.
I also get calls which ring for only a couple of seconds, hardly long enough to reach for my phone before they hang up.
I've heard that these may be scammers trying to trick me into calling back, so they could charge me however many dollars per minute.