Who can just whitelist phone numbers? I get calls all the time from numbers I wouldn't have known to whitelist; colleagues, people in other companies who I'm collaborating with on some project, food delivery people, customer support calling me back, etc.
I usually ignore calls from abroad at least, but even those I can't block; I'm constantly spam called by different anonymous numbers from the UK, but I also have colleagues in the UK whom I want to be able to accept calls from. I once got an unsolicited call from a French number which I ignored, only to find out that it was the phone number of a food delivery person who was there with my food. Just last week I got a call from an unknown German number; in that case, it was a call from a colleague in Germany.
I don't think a whitelist of phone numbers is a workable solution for most people.
I usually ignore calls from abroad at least, but even those I can't block; I'm constantly spam called by different anonymous numbers from the UK, but I also have colleagues in the UK whom I want to be able to accept calls from. I once got an unsolicited call from a French number which I ignored, only to find out that it was the phone number of a food delivery person who was there with my food. Just last week I got a call from an unknown German number; in that case, it was a call from a colleague in Germany.
I don't think a whitelist of phone numbers is a workable solution for most people.