Human supremacist in fantasy novels almost never makes sense when the other races in those stories are empirically better then humans, Elves usually have strong magical powers and long lives living for hundreds of years or even being immortal, dwarves have a mastery of smiting and tinkering, beast races have stronger physical strength, and then there are the dragon or other mythical races like angels and demons. So for humans to claim to be the best race in these stories never makes any sense to me. I know that it usually used as a metaphor for the real world but in the real world there is no major difference in people based on their skin color and thus racism and racial supremacy is usually based on some manufactured idea of a perceived superiority, that doesn't translate to fantasy when there are races with vast differences based on race in those worlds. A human with average magic power and physical strength would find it impossible to win a fight against any other race in a fantasy setting.