It's window on the artist's power in the recording studio, or the engineer in the mixing box at a live event, with the artist's final approval. Of course very old recording quality may be limited for tech reasons.
Best example I like is Stevie Nick's Crystal Visions CD. Perfection in studio and live.
To me adjusting tone controls would be like opening a bottle of wine and adding things. I prefer to take art on the artist's terms.