Just for the record. I am a Reform Jew, a denomination widely known for skeptical or rationalist cosmology. However, i most emphatically do NOT consider Adam and Eve to be "fictional." I consider them to be the earliest known named parents of the lineage that led to Abraham.
Where they came from and how they came into being may be a poetic embellisment, but they seem quite real to me. They are not the parents of ALL people, they are simply the earliest known parents of the Jewish tribe of people.
The Christians who appropriated our religion really did a number on our genealogical records, codifying them as the "infallible word of God" and thus giving the atheists an excuse for a field day of snarky laughter. "Who were those OTHER people, outside of Eden?" they laugh -- "Your story isn't even consistent fiction!"
But, again, as i see it, our religion is not monotheistic, as the Christians would have it ("no other god before me" implies that we Jews were well aware of other gods and of the tutelary nature of our own god) and we were not writing children's fiction, because our interest in genealogy is evident and obvious in every "begat" in the Tanakh, so the "other" people outside of Eden were just that -- another tribe of human beings whose ancestry we did not know.
Give credit where credit is due: We Jews have one of the oldest and most continuously curated genealogies on Earth. Our family tree has been copied over and over, on parchment and on paper. That does not make us "better" or "more special" than other people, but it does lead folks like me to the conclusion that Adam and Eve were real people who actually lived several thousand years ago.
Cheers!