The BT of the 1970s (and 1980s) evokes little affection with punters who can remember those days.
Sadly, I do. Months to get a domestic line installed. Got two buildings either side of a road and want to connect between them? That'll be an arm, a leg and your firstborn child and their firstborn as well, all for 1200 baud.
And then came computer networking - X bloody 25! Design by politicised international committee, making camels look like a utopian dream. Valid implementations that c/wouldn't interoperate. Network addresses as BCD encoded telephone numbers, with up to 100
extension numbers ports available.
Some things I'd happily accept a bit of memory loss to forget.