> Sure, the standard might be lacking, but then the standard should be fixed. As a website author you need something to refer to when you don't experience these issues yourself.
The problem is that it’s the wrong standard that’s lacking. WCAG does the best it can with the web specs, but it can’t just impose a perceptual color space on HTML/CSS, and it would be impossible for mere mortals to evaluate a perceptual contrast standard on RGB/HSL.
But you can easily find A11y articles pointing out where the contrast ratios which pass or fail are very flawed for even people with good vision.