The ones that have stood the test of time are masterpieces of storytelling. They shine insight into a facet of life. They have a strong throughline, a message without moralizing. The best ones ground an experience to make it tangible to parent and child.
Where the Wild Things Are - a fever dream about rebellion and unrealized sexuality, hero's journey into the latent world and back.
Green Eggs and Ham - picky eating works on its own, or can stand in for just about any other unpleasant experience. The repetition mirrors the real-life experience of getting used to something you don't like.
Can't remember the name, about fuzzy little monkey people living in a hut? -
really cozy, about the warmth and safety of being a cuddled-up tiny person without worry.
There's no throughline in this one. The prickly porcupine stands in for a stressed mom. The fairy stands in for a child who messes up the kitchen. The solution is play all day and leave the kitchen dirty? Doesn't hold together.
I'd take out the filler "journey" bit, add in some conflict between the mom and kid, and make the ending more realistic (fairy uses magic to make icing for the cake?). That might bring it up to library-filler tier book.
To me, the art looks really impressive though. Again, no throughline - I'd expect a progression that goes from lonely porcupine -> in the wilderness -> sharing the stage -> back at home but happy