I would think that at moderate listening volume, a neutral sounding speaker, as the human ear is concerned, would have a measurable dip in the upper mids/ lower treble. I believe this why the average studio monitor leans toward brightness and fatigue.
I agree that exaggerated treble is often mistaken for detail. Case in point would be Golden Ear Tritons:
https://www.stereophile.com/content/goldenear-technology-triton-one-loudspeaker-measurements
They have quite a large boost above 10kHz. To my ears, these speakers produced about as much detail as $400 Klipsch towers, yet they were ear-piercing bright. Maybe the brightness was simply masking detail?
I agree that exaggerated treble is often mistaken for detail. Case in point would be Golden Ear Tritons:
https://www.stereophile.com/content/goldenear-technology-triton-one-loudspeaker-measurements
They have quite a large boost above 10kHz. To my ears, these speakers produced about as much detail as $400 Klipsch towers, yet they were ear-piercing bright. Maybe the brightness was simply masking detail?