As someone who does not take Genesis 1 or 2 literally I can tell you why.
The author of the text was not alive at the time of creation. We would have to infer that God revealed that narrative much much later. That is not so hard to believe. But we must also consider the fact that almost all cultures around the world have their won creation accounts. And, they all sound at odds with our current understanding of the universe. For example, the six day creation some six thousand years ago. A rational view of both scripture and contemporary science compels us to
LOOK DEEPER. This takes us to the important realm of Hermeneutics, the study of the general principles of biblical interpretation.
Hermeneutics | Definition, History, Principles, Examples, & Types
God gave us brains to observe and try to figure things out. We have come a long way. We do not know everything, of course. We are still learning. It is indeed possible that Genesis 1 is literal historical truth but it is not likely. That in no way undermines it's importance, meaning and impact. It invites us to look at it from other angles, other dimensions of and to not be satisfied our current interpretation , whether literal or allegorical or anagogical. It is always best to keep an open mind, continue to reflect and dwell with scripture. That means starting with the narrative AS IF it is literally historically true. Then, pondering themes, characters, dynamics, who wrote it and under what circumstances and motives. Then the important question: What is God saying and doing through all this. What is the real revelation to us about God and ourselves.