How is that correct? 10 years ago, it was mostly young folks, college, HS, 20-somethings. There was a good deal of dating-related activity happening, but the vast majority of FB back then was not related to dating.
Certainly people have found romantic partners on FB in the past 15 years, but I would view that as in spite of the lack of dating-related features. Up until now, FB has not been geared toward or especially useful as a dating platform, especially given the availability of dating apps that actually fill that niche.
I think FB Dating has the potential to be way more successful to a mainstream audience than nearly any dating app built to date, though.