This is a fascinating comparison, and I think you’re touching on something many fantasy readers intuitively feel. Rothfuss’s “fae” and Jordan’s Aelfinn and Eelfinn clearly draw from the same deep mythological roots, where otherworldly beings operate under alien rules that feel logical only in hindsight. I’ve always leaned toward the idea that these realms function as parallel or adjacent dimensions rather than distant physical locations, which helps explain the distortion of time, space, and causality within them. The use of bargains, riddles, and strict but opaque laws reinforces the sense that entering such worlds is less about travel and more about crossing a metaphysical boundary. Whether through ter’angreal or hidden doors, the danger seems to come not from power alone, but from misunderstanding the rules that govern these strange realms.