As what somebody else said, simplicity is hard to get it right. Especially in storytelling where it’s easy to embellish a lot of things in the story but harder to simplify and omit what’s unnecessary. This is possibly also true in animation and illustration.
Especially in 2D where it would be that hard to get details right that you have to simplify things instead. (You could get away with detailed textures in CGI and stop motion.) The same principle applies and it works to a generous extent. Especially where it has to be done well enough.