Many parts of rural Prince Edward Island (PEI) has DSL running on a phone system that’s probably original from modernization initiatives in the 1960s - 1980s. Party lines were the norm in some areas up west until late-1980s.
My daughter is gonna grow up not knowing any of the “shared phone line” etiquette because it is largely obsolete.
Some of the first-hand accounts I’ve read talked about neighbours listening in on conversations. People could tell a snooper was on the line because the volume of the other caller would drop. There was a social aspect to the whole enterprise because you could tell the one nosy neighbour to get off the line and the volume would magically raise.