Even before many folks switched to unlisted numbers, in part to evade obnoxious ding-a-ling solicitations, the annual telephone book began shrinking. The migration from landline to cell phones was apparently the final straw, along with Yellow Pages regulars who turned instead to website searches or FaceBook.
What was long a standard reference volume for local communities is now long gone.
When’s the last time you saw a phone book?
Jnana's Red Barn 
sometime between 2016 and 2020…
Tick, tick, tick …
I still have a landline because there is almost no cell phone reception in these hills where I live (although I do use wifi calling on my cell phone). And I still have one old-fashioned landline phone that plugs directly into the phone jack in the wall. If the power goes out, as it frequently does in bad storms, and there’s no cell service or wifi, I can still use the landline to make emergency calls. I live in the middle of nowhere, and I feel safer this way. All of that to say…because I have a landline phone, I receive a new phone book in the mail every year.
The plot thickens.