Phone books certainly have a more limited application today than 20 years ago. I would hesitate to say we don't need them any more, however. There are still people with no or imperfect internet access. Of course, the Boy Scouts will always advise that it's best to be prepared.
What I find intriguing about phone books is that the supply of phone books seems to be inversely proportional to the need for them. Back when you really NEEDED the things - there was one. If something happened to it; it may not be so easy to get another. Often the family phone book was older than most of the children. Today the need for these things is not 10% of what it was - but there's a new phone book on my step, seemingly, every time I turn around.
An ascendant man, living in a degenerate age, MUST, by definition, live in contradistinction to his times.