Hmm, still a little bit confused. Begs the question why the likes of Arcam and NAD do not make any 40Watt or 80watt power amps anymore.
But plenty of manufacturers still do, so the future still seems normal (in this context at least...).
As usual, although I have my A-level in physics, the stuff of HiFi - logarithmic loudness scales, power, amplification, sound floors, sensitivity, sampling rates and bit depth etc etc - still kinda seem like a "black art" to me. And I failed Art!
I also tried to study music with much the same result.
I should really stop worry my pretty little head about it and enjoy the music shouldn't I?