This doesn't seem like such an egregious example to me - I tried it in a colour contrast checker and it passes WCAG AA but fails WCAG AAA for normal size text (but passes for larger text): https://snook.ca/technical/colour_contrast/colour.html#fg=5A...

I will admit I don't find the letter spacing on that font to be particularly pleasant, and if you turn the "Cantarell" declaration off, it does become easier to read (better letter spacing and thicker strokes, which latter contributes positively to the contrast).

> why ... can't you use some darker color for your text?

Just add the "zap colors" bookmarklet from this page: https://www.squarefree.com/bookmarklets/zap.html to a tool-bar menu in your browser (add some of the others for other annoyances if you like). Then when you find a page like this with a non-black color, just poke the "zap colors" bookmarklet and the color will change to black (a few others will change too, such as those pages that like redefining the colors for links, etc.).

Not sure what you mean? Its nearly black?

It's #5a5a5a. That's not "nearly black" is my book.