When I came to Canberra in the mid-70s, dinner parties were very much a mainstay of the social scene, primarily amongst couples of course, but singles were included too, especially if there was someone the hosts thought you could be paired off with!
It’s not that there weren’t restaurants and clubs in those days (anyone remember the Bacchus Tavern?), or that people weren’t as affluent, relatively speaking, as they are now.
I remember the various fads (progressive dinners, fondue parties, steamboats) and the artery-clogging menus as well!
When I hear people who are the age I was then (mid-20s) talk about what they did at the weekend I rarely, if ever, hear mention of a dinner party. Restaurants, clubs, bars, yes but no dinner parties.