Do you answer calls to your cellphone from numbers that are not in your contacts or recognized by you?
I try not to. I never answer a call from the same exchange (first three numbers) as my phone number. I find that the “local caller” phenomenon is also spreading to nearby locales.
I have a harder time with Blocked/No Caller ID numbers because some of my usual callers have blocked their numbers.
Now my cellphone sometimes warns me of a suspected telemarketer and it appears that the carriers are making efforts against Robocalls. Congress has also indicated an interest in new laws to combat Robocalls.

But I won’t let my guard down.
If I don’t answer a call and it’s important, they’ll leave a message.