Physics and data processing. Our eyes aren't actually 24 bit per frame. In fact our eyes are pretty shit. What they're good at is fairly quickly moving and adj

Physics and data processing. Our eyes aren't actually 24 bit per frame. In fact our eyes are pretty shit. What they're good at is fairly quickly moving and adjusting, and are backed by a processor (our brain) that is capable of converting that data into a spatially aware image. In fact our brain doesn't even really see much of the view. It's filling in a lot of blanks based on the understanding of the scene. Cameras are trying to capture that into a still. You can capture multiple stills together with different exposures, but you're going to battle things like motion etc.. Most cameras these days are in the 10-14 bit range which is a function of the range the photosites will respond too before saturating, but also given that most displays are 8 bit, after a point there's just diminishing gains. 14 bits allows for a lot of latitude when shooting and processing.