That raises an interesting point. Maybe, what is being burnt-in is not
the hardware, but one's appreciation of the sound.

No maybe about it.
I visited my friend's recording studio recently. He's spent a lot of
money. Built an impressive shed at the end of his garden. Put a lot
of expensive equipment in it. I was impressed by the sound. For 30
minutes. Then I realised that it really didn't sound as good as my
lesser gear in a better room.