Voadam
Legend
Early D&D did not have a hard fantasy sci fi flavor divide, there was a bunch of occasional blending and juxtapositions such as existed in sword and sorcery stuff like Lankhmar and Dying Earth. Gygax sent his group to Barsoomian Mars for instance as well as stuff like Expedition to Barrier Peaks and the displacer beast being an adaptation of a sci fi story monster.So, why did D&D in its' various editions decided to have psionics in its' fantasy settings to begin with? They could have called it Psychic Magic or Occult Magic like PF1 did. But they didn't.