Astonishing how this article does not once use the phrase "party line".
Party lines used standard telephone lines. The joke was that they had nothing to do with the cost of the wire. The cost of the wire is a tiny part of the cost of installing the system. It was the phone company not wanting to install the switching gear. Sometimes the party line was tied together within BC-Tell's box. So when they installed better switching gear everyone suddenly had their own line. That's different than barbwire rigs that ran over single lines. (BC-Tell is now called "telus")