This isn't the impression I've gotten from looking at agent's manuscript wish lists.
https://twitter.com/search?q=#mswl fantasy
http://mswishlist.com/mswl/fantasy
Look, I couldn't get anyone to take on the first novel I'd been working on forever either. I loved that book and those characters, and got some good feedback from critiquers and beta readers, including some industry pros. But for whatever reason, no one I queried loved it enough to take it on. It sucks, but sometimes (most of the time) the book we loved and got encouraging feedback about is simply not good
enough, or maybe agents and editors have seen too much lately that's in the same vein, and it doesn't stand out from the pack enough.
Once upon a time there was a man who made a bunch of musical and artistic mischief with his friends. He never in a billion years would have gotten a major record deal, so instead he and his friends set out to start a label of their own...and a whole new form of music in the process. His name was Genesis P-orridge and his band was called "Throbbing Gristle." His idea was to make music made from noise given form and he called it "industrial music."
Was their music awful? Depends on who you ask. Would it have been taken by a mainstream label? No way. Was it still enjoyed by countless people and changed the landscape of popular music forever? Indeed it was.
Same with novels. Just because is not taken by a major publisher, it doesn't necessarily mean that it isn't a fantastic work. It could just be that it isn't what the corporate world of New York thinks will add to their bottom lines.
Just as the rise of cassettes, which were easy to record on and distribute without the need for massive equipment to press records, changed the way music was listened to, the rise of ebooks is changing the way people read. I honestly don't even think I ever want a deal with a major publishing house after the horror stories I've heard about editors changing everything and all the pressure and the rest. I would rather sell half as much and own my work and write what I want to write than "sell my soul" to New York.
In a world of people trying to be the literary equivalent of Beyonce, I will be happy to be the literary equivalent of Black Flag or Bathory.
There seem to be a number of recent fantasy authors who write books that aren't set in the middle ages. Have you heard of NK Jemisin, Saladin Ahmed, Ken Liu, Django Wexler, Brian McClellan, Mary Robinette Kowal, Kate Elliott, Elizabeth Bear, Nnedi Okorafor Malinda Lo, Kameron Hurley, Sarah Monette (also writes as Katherine Addison), Aliette De Bodard, Cindy Pon, Naomi Novik, Zen Cho? This is just scratching the surface, and I believe these authors are all signed with large imprints. Actually, I'm having a harder time coming up with recent breakout authors who write in medieval-European-type settings.
I've even been told that the kinds of settings you mention are saturated right now that it's especially tough for someone who does want to write in a medieval-ish setting or who has an UF book with vampires or shape shifters.
I've been told the opposite. I've had one agent I met at an event say that all the things that make this one setting I have unique basically has to go if I want it to stand a chance. And most of those authors still write a variation of the past, like Saladin Ahmed in medievally Arabia (reminds me of an old D&D setting) and Cindy Pon's China-like world.
NOTHING AGAINST THOSE AUTHORS! Don't get me wrong. They are all talented and there are only a handful of authors I will openly mock, but what they write just isn't unique enough for me.
The bottom line is art should come first and if some company doesn't want to pay for the art, one can always sell it themselves.
Take my "literary splatter novel", that is as much about ethics and family as it is about a demonic hero who eats souls and tears his opponents apart in graphic detail. By its nature it is NOT going to be picked up by any major publishing houses, but I still like it and I will DIY it. I would advise the OP to do the same if they really believe in their art.
It took a long time, but the DIY ethic is finally getting popular among writers, and that is a good thing. Who needs to appease the whims of the gatekeepers when one can just tunnel under the wall?