If you are a thoughtful reader of scriptures you’d see immediately that two ignorant innocents expelled from the Garden in Eden wouldn’t know a thing about basic survival. Clearly, there’s more to the story.
I completely agree that the Ten Commandments are a reinstitution of what must have been lost or forgotten.
In Exodus 20, when God speaks to the assembled Children of Israel, it is they who interrupt, telling Moses to speak for God. Moses relates instructions to offer sacrifices and civil laws, which carry the authority of God Himself.
The ‘Ten Commandments’ (which aren’t called that in the Hebrew) were not new. Hearing them coming from God Himself was an admonition that such laws came from God, not just from human reason.