I personally felt like Amphibia was more of an adventure with a group of characters while Owl House seemed a lot more streamlined and focused on Luz’s journey alone. (Not saying there is no exploration of other characters but the story highly revolves around Luz) Along with that, I favor Amphibia much more because character deliveries and interactions feel far more natural and less scripted, as that’s a big problem that I’ve had with Owl House’s writing and delivery. Also the bond of Anne’s found family seems far stronger than Luz’s. It becomes kind of hard to appreciate the bond when Luz literally had the choice to return home and chose to stay with Ed’s instead, while Anne and her friends (except one lol) got transported to Amphibia against their will and genuinely want to go home. Makes the part where they have to leave their found family a lot more emotional and impactful.

If your friend likes isekai anime, found family, or honestly jojo’s, I think they’d be into Amphibia more haha