Are we happy with just arguing, or should we argue about the same thing?
Everything that comes out of your speakers and reaches your ears must be measurable. If not, your speaker cones would not have moved, and neither would the bones in your ear. All forms of measurement.
When is that fact useful? If, for instance, you insist that music sounds better on a Thursday, I prefer Wednesdays, and someone else says neither can can possibly have any effect whatsoever.
If we can afford the time, trouble and expense, we can put it to test.
Otherwise it is not important or relevant. We just enjoy music, or we enjoy comparison of equipment by subjective means.
The most important spec of an amplifier is its power rating.
Can it move the speakers; will it blow them up? Is is dangerously under- or over-powered? Yes, I know there more to it.
If we were really concerned about the power output of our amplifiers, we would probably have to measure it for ourselves. Are you any more trusting of what marketing departments write than I am?
Whilst, ultimately, it is all about music, there is another side too. I spent a lot of Saturday appreciating equipment, but very little of it appreciating music!
If I ever get the chance to take your recommendations on amplifiers and speakers, the very last thing I would talk about is numbers!