Yes, an excellent point, but it doesn't go far enough.
The same comment can be made for "ANY" component in the reproduction chain, including the room.
In fact, Power Conditioners have limited to large effects, depending on their type and the Power Problems any one individual might have.
My mind has wondered to that very "sum of its parts" (including room and tweaks) idea many times, since I have heard "EXTREME" differences in similar or same components in different systems.
Even further are those who suggest "they" know what a component in its current incarnation "sounds" like, after hearing it years ago, before several changes, or improvements.
Cables, Connectors, Acoustic Treatment, Vibration Devices, Coupling Devics, System Set Up, Listening Position and Field, TUBES, etc, can all make so many changes to the sound that is almost seems futile to pay any attention to what anybody writes, or to a large degree even listening in any system but your own.
(and then only after sufficient break/burn in)
Such is our lot.
