Why do raw files opened in Lightroom seem to almost always require massaging with the highlight and shadow sliders to look perceptually correct (that is, to reproduce what my eyes see in reality)?
I notice that virtually everyone I have seen edit photos in LR (e.g. on YouTube) lowers the highlight slider and increases the shadow slider to "recover detail" in order to mitigate this effect. Why is this necessary to create a realistic image? The camera sensor sees the same photons I see, and while there's a gamma curve correction to account for the fact that the human eye doesn't perceive light in a linear fashion, that still doesn't explain the need for these strange local tone mapping adjustments.
Alternatively, am I wrong, and can one get a nearly "realistic" image without touching these sliders at all? Obviously, if overdone it creates the "bad HDR" effect. I am trying to understand why their use is so common.
edit: Actually, I suppose the same question applies also to global contrast adjustments via the tone curve, since this is just a global tone mapping. And I guess "behind the scenes" what LR does with the shadow/highlight sliders can be roughly understood as some kind of tone curve manipulation.
So, more broadly, why do raw files require significant tone curving to look "right"? In Camera Neutral, for instance, they seem flat and lacking contrast. But again -- I should be seeing raw sensor data with basically just a gamma correction, and the sensor and I are seeing the same photons, so I expect roughly the same result. What explains the discrepancy? Surely some lack of microcontrast can be attributed to Bayer interpolation and the AA filter (if present), but that's not really what I'm talking about.