Now with your $3k speakers and $20K amp (Monads I presume) combo, how can you tell where the actual weak point was? With a different speaker (not saying more $ or less), the $20K amp may have performed closer to the $100K amp, maybe not. We each just know what we like, our preference of sound, at what we are willing to pay for it.
The Monads were amazing with every speaker with which I heard them paired. I own more than one pair of speakers and I've heard them drive others at trade shows, so there is some width and depth to the foundation upon which my perception of and beliefs about them is based.
As for the proverbial weak point, perception is reality; to me, there was no easily quantified "weak point" and I spent years looking for precisely nothing to change about the system. The sound was simply superb from top to bottom IMO. Since I'm the guy paying the bills and doing the listening, my opinion of my system is all that matters, right?
To ensure my position is clear, I'll say I've yet to hear an amp I like
better than the Monads regardless of price, pedigree or specification. They were special, and as luck would have it, I had just the speaker for them.
I believe the crux of our disagreement (for lack of a better word) lies in how we view the relationship between price and performance. My experience is that the two are not in any way related, but your journey seems to have led you to a different conclusion.