Cashore's novels have the problem that they're mostly kind of... bland, with respect to the worldbuilding, in addition to being incoherent in the ways I've already described.

Yes, this, exactly. There has always been something very ... mechanical to me about her worlds. I also get the sense of containment, like all there is of this world exists on the page, and if you walk off the edge of the page there's ... nothing.

Link very illuminating, thank you.