I've always associated that sentence with Google Fonts, since I first encountered it on their site and they use it for previewing the fonts they provide.
Hmm, good question...it definitely was years ago that I first saw it, but I'm not sure how recently the last time I remember seeing it is. Taking a look now, I think the entire site seems to be different compared to when I last looked at it; the layout is completely different, and I don't recall it having a dark mode before.
