For output of SDR content in a typical context on recent displays with small pixels (e.g. "retina" displays), a high-quality-dithered 8-bit image is visually in

For output of SDR content in a typical context on recent displays with small pixels (e.g. "retina" displays), a high-quality-dithered 8-bit image is visually indistinguishable from a dithered 12-bit image. But for image editing, 16-bit integers or single-precision floats are certainly helpful. And for HDR and wide-gamut images, 8 bits gets a bit limiting.