To what extent are the cumulative distortions in the electronics chain masked by speaker distortions? My WAG is that they are completely masked, presuming the electronics are even halfway decent, but that's just a guess. And even if they aren't, their audible contribution to signal reproduction must certainly be minimal.
I've had the same thought and have built my system around the assumption this is true. I wish I knew.
I'm surprised that more attention isn't paid to this question, because it so plainly would inform how a person ought to spend their audio budget.
My speakers are far nicer than my other components, and I often wonder whether I would hear a difference if I upgraded my amp. My guess is maybe -- quite possibly not -- especially as I don't listen to a lot of power-hungry bass music.
FWIW, I run Revel F208s off of a relatively cheap AV amp (Onkyo TX-NR686, purportedly with 100 watts per channel (2 channels) at 8 ohms; 0.08% THD).
Signal source is Roon, with DSP filters set up using REW, using a $140 DAC (SMSL Sanskrit Mk2), a Raspberry Pi, and plain speaker wire. No sub engaged when listening to music. No room treatments other than furniture placement. The speakers are the highest-end component by a very wide margin.
So what do people think? Should the speakers be more than ten times the cost of the amp, assuming basic power needs are met?