Telephone equipment used to belong to the phone company, not the customer. Phones were leased, not purchased. If a customer moved, the phones couldn't be taken from the house. If a customer needed a new phone, the repairman brought it and took the old one. The number of phones and hookups per house were limited.
If you watch old movies, notice that even the wealthy families didn't have phones in every room.
The first time we had two phones in our house was when I was 16 years old. We had a wall phone in the kitchen, and a table-top phone that could be plugged in to a few different rooms. My brother got the wire and connections from Radio Shack and put them in so we could move the phone.
Eventually, when the FCC told AT&T that it had to break up its monopoly, people were able to buy and keep their own phones. They opened up the Phone Center Stores in malls to sell their phones. It was revolutionary!
AT&T charges elderly widow $14,000 in "rent" for rotary phone - Computerworld Blogs