[I]t’s also worth considering that Amazon is literally not your publisher. (I mean, they’re mine, but as Skyscape.) Amazon does very little for you except act as a receptacle for your book. Which might be genius. Which might be dogshit. They literally don’t care. It’s a socket and into it you can shove diamonds, candy, cat feces, bezoars, babies, whatever. The reason they don’t take a lot of that coin is because… they don’t do anything for you.
–Chuck Wendig reminds you the reason Amazon pays “publisher-level royalties” to authors is because its “authors” are publishers.
Skyscrape, for what it’s worth, is one of Amazon’s actual publishing imprints. This is not Amazon’s selfpub stuff that anyone can jump on board. Imprints like Thomas & Mercer, Skyscrape, 47North, and so on are exactly as “gatekeeper”-ish as “traditional” Big 5 imprints, which is to say you will need a traditional literary agent to get you through the door… and will sign a traditional contract with traditional royalty payments to boot.