One reason I think Spongebob worked so well was because the show had a mix of relateability and fantasy. The characters had jobs and houses and "cars" and all that, but the fact that they were sea creatures factored into the jokes and stories frequently. Compare this to The Berenstain Bears. They're just people with fur. It doesn't matter that they're bears. If you made them human, then as far as I'm aware you'd just have to give them shoes and make the dad not like honey so much. Same with Arthur. The anthropomorphic thing adds nothing except making the characters look weird and giving them bunny ears and antlers and stuff. Compare to Pony. Again, a lot of aspects are relateable to our world, but they have wings and magic and mythical monsters and such, all of which influences the stories. It wouldn't be the same show if it wasn't these creatures in this world, and that applies to Spongebob. I think that's part of why shows like Spongebob and MLP have an adult audience while shows like The Berenstain Bears and Arthur do not. At first it just seemed like it was because Spongebob was funnier than those other kinds of shows, but MLP is all soft and cute not a straight comedy similar to PBS Kids fare and it works for adults so I started looking for other differences.