Unlike 4:2:0 it works well as a packed format (e.g. Y0 Cb Y1 Cr), and unlike 4:4:4 it's a simple 2 bytes per pixel (packed 4:4:4 either uses an uneven 3 bytes p

Unlike 4:2:0 it works well as a packed format (e.g. Y0 Cb Y1 Cr), and unlike 4:4:4 it's a simple 2 bytes per pixel (packed 4:4:4 either uses an uneven 3 bytes per pixel or wastes 1 byte per pixel...) Which led to a lot of simple and professional HW/SW being designed for packed 4:2:2, so codecs support 4:2:2 to fit into professional pipelines.