I think part of it is that even though we have seen very little of it, Owl House's premise is more interesting than Amphibia's. With the Owl House, we know Luz is in a demon world where there could intentionally be any number of creepy and wacky demons, witches, etc. Plus there will be a witch school, and since Eda seems to be an outlaw, there is probably magical police looking for her as well. Who knows what kind of crazy world to expect?
With Amphibia, all we see is a wilderness, and the only apparent civilization is a tiny podunk village of cutesy frogs. I have a feeling there will be more to it than that (I doubt those ruins in the intro are just for decoration) from just from first impressions, Amphibia's world doesn't seem like it will be as "deep" as Owl Houses.
Also I think people find Luz more attractive than Anne, although I think they're both qts.