If 99.9% of your users don't turn on a flag, then as a web designer, it doesn't exist. Saying "it's there behind a flag" is utterly useless. It's something web designers need to depend on, not users.

And who likes oversaturated colors? What user rage? I've never heard of any of that. To the contrary, it was a huge problem that in Firefox, image RGB values didn't match CSS RGB values on P3 displays. How the heck are you supposed to create an interface with, you know, colors that match? Kind of a basic requirement. Thankfully, they finally fixed it. Why it took them 12 years is beyond me, though.