Chroma subsampling is a terrible idea for non-photographic images. People are not "terrible" at color perception. I can clearly see its harmful effects to on-screen captures, line art, anime, 2d video games, or even Super Mario 64's hat.
Youtube's chroma subsampling makes colors bleed, Mario's hat turn into chunky red blocks approximately filling Mario's hat, screen captures discolored and grainy around text, and sharp colored anti-aliased lines turn into a discolored mess.
(Mario's hat was pixelated on pannenkoek2012's emulated SM64 videos at native 640x480. Maybe newer video decoders antialias the chroma channel, so Mario's hat is not pixelated but "merely" blurry.)
I upload oscilloscope videos with colored lines on black backgrounds, and stopped using brightly colored lines partly because color was being blurred and discolored by Youtube chroma subsampling.
Youtube's chroma subsampling makes colors bleed, Mario's hat turn into chunky red blocks approximately filling Mario's hat, screen captures discolored and grainy around text, and sharp colored anti-aliased lines turn into a discolored mess.
(Mario's hat was pixelated on pannenkoek2012's emulated SM64 videos at native 640x480. Maybe newer video decoders antialias the chroma channel, so Mario's hat is not pixelated but "merely" blurry.)
I upload oscilloscope videos with colored lines on black backgrounds, and stopped using brightly colored lines partly because color was being blurred and discolored by Youtube chroma subsampling.