Fantasy art is one of the most prolific fields in representational art. There has always been work, if for no other reason than pulp fiction magazines and comic books. Frazetta and others got a lot of work that way, which helps to buy the beans while you dp other things.
It is also one of the fastest growing fields--it's hard to keep track of all the established artists and the newcomers. Here's just a few of ones with whom i am familiar, and they are probably now to be considered "from days gone by:"
Greg and Tim Hildebrandt
(They did a lot of Tolkien themes--here, Ghan-Buri-Ghan meets with King Theoden.)
I think the erotic component is a product of the early pulp magazine days.