Gamma curve is needed due to the fact human eyes are more sensitive to darker areas than the brighter areas (Stevens' power law), so with gamma you can get away

Gamma curve is needed due to the fact human eyes are more sensitive to darker areas than the brighter areas (Stevens' power law), so with gamma you can get away with lower bit width without (perceptually) introducing noticeable banding. The fact it somewhat matched with a response curve of CRT seems to be a historical coincidence, based on multiple sources I've read in these years. I do agree we should have get rid of it at this point as it introduces many errors in color blending. > Log formats do this, but because the order of magnitude of light is more important than the absolute value, it takes the log of the value. It's a more efficient use of bits in the storage / transmission. It literally is what gamma curve does, ina slight different but mathematically equivalent way. "Order of magnitude of light is more important than the absolute value" is exactly what Stevens' power law describes.