More relevant to the topic at hand, it’s extremely rare to receive an unsolicited call to an American phone number from a number outside the +1 country code. So I’m sure when an immigrant in the US gets an unknown call from their home country code, they can be pretty sure the call’s intentional and worth answering
Can't be THAT rare, can it? Isn't 15% of the current population in the US immigrants? Most of us immigrants do receive and make calls to our "mother country" every once in a while, even introverts like me. Or maybe you were excluding immigrants in that as you mention immigrants later?
Surely this would be covered by the fact that you're making calls as a "known number" not an "unknown number"?