Something has been picking at my brain for a while, and it's something I will fully cop to being somewhat complicit in myself.
Why is the fantasy genre stuck in the Middle Ages?
More specifically, why is most secondary-world fantasy set in a technological and sociological equivalent of the Middle Ages?
I mean, sure, there's some variation-- for some books it's more of a Renaissance, and some move out of a Western European mold for Arabic or Asian flavors, but the technology and sociology is pretty much a given. I remember being slightly thrown reading Amanda Downum's Drowning City when she had characters using single-shot pistols, and then I thought, "Well, why not?"
Now, I've tried to tweak that, personally. Maradaine, and by extension the rest of Druthal, has more in common with Dickensian England than Elizabethan England-- save a lack of gunpowder weapons and steam engines. (Though, to an extent, I have created it as a world where either of those things could be poised to emerge in the very near future.) But, even with that worldbuilding flavor, it's not so out there that people won't be able to latch onto its Traditional Fantasy/Western Europe/somewhat clock-punky vibe.
What's funny is we DO accept fantasy of a different tech level just fine-- fantasy tropes in the modern world is what Urban Fantasy is all about, after all. But those are consistently set in our world, tweaked with magic and vampires and other fantasy elements.
Is anyone doing secondary-world fantasy that really hard-twists this paradigm? I can think of two: China Meiville is one. And Neal Stephenson with Anathem. But the latter was more alt-Earth sci-fi than fantasy.
I'd really love to see something in full high-fantasy mode, but set with WWII tech. Or science-and-magic fueled Race to the Five Moons.
Which brings me to another point. Not only is our idea of technology in secondary-world fantasy somewhat stagnant, but secondary fantasy worlds tend to be technologically (and sociologically) stagnant. For how many books are things more or less absolutely the same for millennia? Even to the point of the same borders.