The most popular fairy tales also have been modified to be more kid friendly. Nobody saved Little Red Riding Hood. Sleeping Beauty wasn't kissed, she was raped in her sleep and gave birth; it was her child sucking the needle out of her finger that woke her up.
These used to be more than just stories for kids, but modern fairy tales are rarely ever told to an adult audience anymore. For many fairy tales, the happy ending was added centuries after they spread.
Try looking on youtube for a version of "The Boy Who Cried Wolf" that ends with the boy being properly eaten. They've all been changed to have narrow-escape happy endings, wholly destroying the point of the narrative.
I think the popular mistake is to assume that every story in folklore collection must be for children and we must be able to derive some moral message out of it. This was time before TV and youtube. Adults told each other stories meant for adults and kids might or might not listen.
These used to be more than just stories for kids, but modern fairy tales are rarely ever told to an adult audience anymore. For many fairy tales, the happy ending was added centuries after they spread.