Great question.
I've always been interested in this since hearing of the infamous 1985 Stereophile Bob Carver challenge.
For those unfamiliar, I won't spoil it, but their honest conclusion speaks volumes.
Hey, it was the days of J. Gordon Holt. Different times.
"But whatever Bob, and others who can match his technical virtuosity, choose to do with the results of this project, I think that the field of high-end audio amplifier manufacture will never be quite the same again. High price and high status will continue to be handmaidens in audio, but the knowledge that high performance and high price need no longer be inseparable cannot help but impair the glamor of cost-no-object power amps.
We're still a little bewildered around here about how all this turned out. Not the way we expected. But that's the way it was."
https://www.stereophile.com/content/carver-challengeMore here.
https://forum.audiogon.com/discussions/the-carver-amp-challenge-and-the-21st-century-and-it-s-failur...