A question I suspect reveals a lot of ignorance...

I'm not posting this to start an argument. I equate this from a mechanical view.Consider the life of a gas powered motor vs. a diesel motor.Higher rpm's equals shorter life span.Simple idea.
A good question. If we could get someone that absolutely knows the answer,it would be great.

After further thought on this, I recall an article that said the power output devices in an amp are running full tilt all the time and the source/preamp is what controls input. Or something like that.
Which at one time some cd players with volume control didn't have enough output voltage to drive an amp to full power.