I vaguely remember reading years ago (when phone books were still a going concern) that a surprisingly high percentage of people actually did have their numbers unlisted.
It’s certainly a reasonable question to wonder why they listed addresses as well as phone numbers.
Has it ever occurred to you that delivery drivers, plumbers, electricians, and actual acquaintances have a legitimate need for that information? And that publishing that information in a readily-available form is incredibly convenient for people?
It’s also that the information (about your address and phone number) was published, but in paper form and not easily found. So, for instance, the public library might have a collection of phone books for all the cities in your county, state or even for the larger cities. (They also had a thing called a reverse telephone book, which listed people by address rather than by last name.)
I have a relevant anecdote. When I lived in the western suburbs of Cleveland, we got, in addition to the regular Yellow Pages and White Pages, a directory called the Orange Line. This book not only had Yellow Pages and regular alphabetical White Pages sections, it featured an alphabetical listing of streets in the six- or seven-suburb region. Each street’s portion, in turn, featured a list of addresses (in advancing numerical order) and phone numbers.
One day, I got a call from a plumber. He apologized for bothering me, then explained that “Amy Davis” lived on my street and he was trying to call her, but her phone seemed to be off the hook. He asked if I could go to her house (which happened to be directly across the street) and explain the problem. I agreed, walked over, and rang the doorbell. When Amy answered, I let her know why, and she soon discovered her phone was indeed off the hook. A few minutes later, a plumber’s truck turned into her driveway, so apparently I “saved the day” in a sense.