Self-publishing is terrific for authors who can and will arrange their own editing, formatting, book covers, and marketing. And many of them can. But a great many would rather
write, and hand over a portion of the proceeds to whomever will tackle the "convert manuscript into book" steps they'd rather not bother with.
Also, the public would generally rather buy something they know something about--even if that's just "it's part of SuperNewPublishing's fantasy adventure line."
Random books by totally independent authors are an acquired taste; you kind of have to love missing commas, homophones, and
eggcorns. Also, it takes an affinity for plots that meander and never arrive anywhere, drastic shifts in point of view, and long, intensely detailed dialogue followed by a two-sentence description of the crucial action scene. If you're willing to put up with that, you can sometimes find *incredible* stories that'd never get past a publisher, and literary experimentation that can make you rethink everything you know about how textual stories should be told. (And hey, the incredible stuff usually isn't always the stuff that sucks--but you can't find it without wading through the slushpile.)
We will always need publishers for:
- The jobs some writers don't want to do, and will stop writing if they have to
- To tell the readers what kind of book this is, because sometimes you want to know if something is a romance or a murder mystery before the third chapter
- To pay the up-front costs that writers can't afford: research, photographs, licensing of previously-published materials
- To notice a market demand and seek writers who'd be willing and able to fill it, but don't know the demand exists (esp. for nonfic)
But we don't need publishers for all kinds of writing, and now a lot of authors can explore other options for those books. Authors can discover how much audience exists for murder mystery erotica, and books written in second-person point of view, and 18,000-word stories that were always too big for magazines (unless they were serialized, chopping up the flow) and too small for print.