If brightness and gamma are disabled in the future some king of night vision/adaptation to darkness should be implemented. If you go on a camping trip or fishing and the sky in not cloudy or totally moonless your eyes adapt pretty well to the dark. I once even went to a bicycle cross country trip during a summer full moon night and you could even see the shadows cast by the moon. I'm just saying that if the brightness controls are disabled, some visibility should remain. In RL you wouldnt be stumbling blindly unless its a cloudy night with no moon.