I doubt it's over. Facebook has their constellation of of apps and services. And the cost of switching is not so simple for, say, the average user who's used facebook as their photo and video archive over the years. But most of all they have the opportunity to pivot, reinvent themselves to keep relevant. Something I wouldn't count them out of. Personally, I hope they fail. The last two years have seen my feeds turn into majority hate filled posts full of vitriol for some issue or other. Only a minority seem to actually be relevant for keeping in touch with friends and loved ones.