> It is quite absurd (but categorically true) that the quality of audio that folks were generally listening to in 2005 was better than what we are doing today.

I seem to recall most people being perfectly content with 128kbps MP3s on iPod earbuds back in the day. Only audiophiles/nerds (of which there seem to be more now) were into actual headphones and amp setups and there's never been greater market choice in this regard.