Elle, let me recommend Malcolm Gladwell's book The Tipping Point to you. It is about the three things necessary to go viral: law of the few, make it sticky, and context.
You bring up a lot of good points, but I'm thinking we are missing a lot of unreported authors. There are Amazon self-pub folks making $50k/mo, and there are writers on Medium also getting that much (between $30k-50).
You're spot on about the 1k true fans...as long as some of those fans are either mavericks, mavens, or salespeople (as Gladwell says).
Love this article. I bookmarked it and am now following you. Looking forward to reading (or at least buying) your book.