Perhaps I need to re-word what I tried to say in my post #79 - why I asked about the definition of "better' In this case.
Limits of human hearing have been researched pretty well by now, which research standard took a sharp upward route by the advent of modern analysing instruments. With respect, faster transistors, 'better' (that undefined word again), components, etc. will not necessarily make a better amplifier possible, in terms of audio quality. As said, it was pretty possible in the 50s to design audio equipment, the difference between which and the live programme could not be readily discerned (documented reports related to such saw the light in the early days. I myself was part of such tests - proper ones.) It is in fact because of the very use of technical nonsense/snake oil audiowise, that firms sell their wares using terms which have nothing to do with audio quality. There are no substantially new achievements audiowise to take into account that could not be reached say 60 years ago. Again as said, the desired quality and reliability could be reached easier nowadays. (Also, again I limit my commnts to amplification. There are more important links in a domestic system, but development re those opens the field way out of reach for a discussion such as this.)
Audio amplifiers are not instrumentation amplifiers. Obviously modern types of the latter are better, more reliable, whatever. Specs of s.s. amplifiers are also better - the point is whether such is required for audio. Figures for distortion 100 + times better than required, damping factor into many hundreds, frequency response level to over the hill better than what is audible, fancy noise limiters equalisers ....
Yes, as JoeESP9 said earlier, engineers might interpret some of the modern attitudes negatively. We are not physicists, we need to constantly take the real world out there into consideration to be successful.
And again P.S: In my examples I talk of what is/was possible. All will know that, sadly, there are examples on the market falling quite short of what could be reached - then, and now. In that sense one obviously needs to compare the best of both eras.