Doctors, dentists, moving companies, home improvement contractors, recruiters, etc. These are some of the most important phone calls I've received in recent memory.

I don't know what world you live in, but I religiously block phone numbers after just one spam call. And I usually don't give out my phone number. (I'm much happier giving out email addresses since I have an infinite supply of addresses.) I never get enough spam calls that I feel like the phone system is going the way of the fax machine.