[PaulHoule]

In particular I believe the problem emerged circa 1995 so there must have been a technological and/or social change.

My impression was that the upgrade treadmill for computers started to get established in the late 1980s.

That is, even though they produced a huge number of computers in the Apple ][ line over about 13 years

https://en.wikipedia.org/wiki/Apple_II_series

you couldn't say any of the newer computers were that much better, particularly in terms of raw performance. It was the PC clones that decoupled the system clock from the video clock making it possible to release a machine that was clocked substantially higher than what you could get six months ago, enough that you could buy a new computer in two years that was more than twice as powerful as your old computer.

Circa 2006

https://en.wikipedia.org/wiki/Dennard_scaling

broke down and the industry has had to multiple cores, GPU acceleration, etc. to be able to make the case that today's computer is better than the one you had before.