alt Hacker Newspeak western society ended back then maybe around the time the first Concorde airplane flew for the first time.
This seems a bit arbitrary to me. Why 1969, exactly? Personally I'd go for the "democratization of Internet" as the start of the slope. So perhaps 1989 ("1989: Quantum Computer Services and Apple end their partnership. Quantum Computer Services renames itself America Online. Two years later, America Online for DOS is released, and a year after that, America Online for Windows.")? Or arguably even a bit later...
You and the GP are effectively in agreement. It's not so much about when the exact peak was but about whether there was a peak and whether or not it was somewhere around that time.