How should we understand myth? Myth may mean a falsehood, or an idea that is out of date. But that certainly isn’t useful. There is another sense of the word “myth” though.
Suppose you don’t understand the technicalities of electricity and someone wants to explain them to you. To explain the flow of currents, he compares it to water. And because you understand water you get some idea of the behavior of electricity. Or if an astronomer wants to explain expanding space, he’ll use the metaphor of a balloon. A black balloon with white spots, representing the galaxies. And then if you blow up the balloon, they all get further away from each other at the same speed as the balloon blows up.
In neither case are we saying that electricity is water, or that the universe is a balloon, with white spots on it. We’re saying it’s something like it. And so in the same way, the human being has always used images to represent his deepest ideas of how the universe works and what man’s place in it is.Alan Watts, the Image of Man
This type of understanding of myth is well established
A more technical and narrow sense of myth that is often used to describe biblical stories, especially miracle stories, is that of a literary genre that includes fantasy, talking animals and stories of the gods. These are supernatural stories that are not literally true, nor are they meant by the storyteller to be taken as literally true, but as a way of explaining natural facts by supernatural (or natural) fictions. Both supernatural stories of gods and talking animals, and natural stories like Jesus’ parables, fit in this category.
A much broader, but still technical and professional, use of myth is “any story” meant to articulate a worldview.” This sense would include both literally true and fictional stories, but it is usually used with the connotation of fiction.Handbook of Christian Apologetics: Hundreds of Answers to Crucial Questions by Peter Kreeft, Ronald K. Tacelli
Myths in this sense are quite useful, because they can illustrate universal truths, without people getting hung up on the details, the characters, or the singular personalities in the story.