Thanks very much atmasphere for your knowledge...
I was hoping your explanation to confirm my point...
I could not explain all the details like you did...
In a word there is tube amplifiers and some S.S. which were never bright or harsh, like my Sansui AU7700 and some new technology now for the last decade...
My point is that there is now available many good different types of amplifiers... Yours for sure and some others...
It is more easy to look for one and buy it now than to solve all acoustic problems for us...
My point is acoustic is the key to optimize and put at their peak level ANY amplifiers working PERCEIVED EXPERIENCE in a room in a way that is astounding, not a minute upgrade...
Thanks to you for your useful post...
This has been what has kept tube amplifiers in business the last 70 years since they do offer a way around this issue (they make enough lower ordered harmonics to mask the harshness of the higher orders they also make).
But in more recent times semiconductors have advanced to the point where you can get rid of that pesky brightness/harshness for which solid state is known. IMO we’ve only just arrived near the top of the R&D sigmoid curve in audio in the last ten years or so.

