The two creation stories, together with much else in the OT, are indeed mythological rather than literal. This does not mean that they do not contain truth, but I suspect it is not the kind of truth that literalists can recognise. Perhaps if I compared them with the parables of the NT it might be easier to understand. Parables tell a story in order to convey a message, but we do not have to believe that the parable actually happened in order to learn from that message. There may or may not have been an actual Good Samaritan. There may or may not have been a man who built ever bigger barns and then died. There may or may not have been a woman who lost a gold coin and then spent ages looking for it, or a man who found a pearl and sold all he had to buy it. The truth of these stories is there, regardless of the fact that they are stories.
It is the same with mythology. We can learn from it, regardless of the fact that the events in the story never actually happened. To admit that they did not happen does not take away from the meaning, or the kind of truth they contain. It just means it is a different kind of truth.