That's a bit like saying that we shouldn't use lossy image/video compression.
Do you realize the amount of 'waste' that a 32bpc†, 4:4:4, imaginary color triangle gamut picture would have ?
†it looks like the human eye has a sensitivity of 9 orders of magnitude, with roughly 1% discrimination (so add 2 orders of magnitude). So, looks like you would need at least 37 bits per color with a linear coding, the overwhelming majority of which would be horribly wasted !
I have no issue with lossy compression; but things like 4:2:0 aren't really typical lossy compression. It's like calling resizing an image to half its resolution "compression".
Also lossless compression can reduce plenty of "wasted" bits already (see: png vs bmp).
But they are ! Like other lossy forms of compression, chroma subsampling takes advantage of the human visual system's lower acuity for color differences than for luminance.
Do you realize the amount of 'waste' that a 32bpc†, 4:4:4, imaginary color triangle gamut picture would have ?
†it looks like the human eye has a sensitivity of 9 orders of magnitude, with roughly 1% discrimination (so add 2 orders of magnitude). So, looks like you would need at least 37 bits per color with a linear coding, the overwhelming majority of which would be horribly wasted !