Ukraine is of course no major market for Facebook, but it's a good example that doesn't match what you describe at all. In Ukraine, Facebook is the place where you follow top journalists, anti-corruption people, activists, and other public figures. It's basically an extremely valuable addition to the media, where anyone can be lifted in popularity in a matter of hours if their content is truly important. Facebook has been an invaluable tool during the Maidan revolution in 2014 combining its social and video-streaming capabilities. It works in times where media is breaking down, being bought by oligarchs, and isn't to be relied upon.

I don't see any alternative that would replace it, in terms of being social, everyone being present on it, and allowing long text+image+video content to be posted and spread easily.