By contrast, in December, I had these time-sensitive calls from unknown numbers: airline lost luggage delivery, Amazon delivery who couldn't get in, my kids' do

By contrast, in December, I had these time-sensitive calls from unknown numbers: airline lost luggage delivery, Amazon delivery who couldn't get in, my kids' doctors, my pharmacy, someone from my accountant's firm, a bank rep, and a few organizations returning my call. December was a typical month, if a bit slow. In theory, I could get a voicemail and then follow-up, but that would result in significant time wasted for both sides (e.g., calling doctors again or setting up re-delivery), and the total time I spent on dealing with spam calls is ~1 minute (5-10 seconds x 5-10 occurrences).