This is the only necessary reasoning that applies for the story. I always thought that the story was odd and was not satisfied with those arguing against it by asserting that floods occurring all the time as a significant contribution to it. They didn’t need that story to explain any flooding, no matter how devasting some would have experienced any. It was only the fossil evidence that needed some justification that made this and other stories essential to make sense of with respect to questioning our origins.
Fossils would have been a shock to many and the evidence of such water-based creatures was what led most to theorize an Earth that begun under water. This actually was introduced in Genesis’s creation introduction that begins with assuming the void and then a separation of the “waters” above from the “waters” below. [The actual term for what has evolved into the biblical term, “water”, had to have actually been fluids in meaning.]
They also intepreted life as coming from water initially (and correctly). BUT,…the “Noah’s Ark” story was also what made most pre-scientific and other reasonable secular minds to also notice the giants below a certain level in the then known geographic layers, which had a sudden dissappearance, and thus the recognition of a pre-human stage that evolved into the stories about a dual level set of gods such as the Greeks maintained in their own pantheon of ‘gods’. They needed to guess how and why these giants are no longer around. Thus, the Ark story, a common secular explanation by all most travelled peoples, had entered into the accepted origin stories of the day. […and wisely so!]
So, this particular story has nothing to do with the fact regarding common floods but ONLY to the fossil records, even if we lack any direct evidence of this in historic records. There likely existed those who collected such evidence as proof but likely destroyed by the time of Christianity.
Note that the religious do not appeal to the science. So while it might entertain the non-religious to presume it helps, it doesn’t. I found the most effective way is to demonstrate how the stories can come about without a religious interpretation, by showing how the names and other words used actually hint at the secular roots of words we even use today in many languages, and any ancient wisdom by actual intellectual scientifically minded people. But just as children are impatient to pay the needed time to understand the logic, the stories would get passed on without care until an overwhelming amount of illiterates later on had lost the use of both the words and the prior historical relevantce as it relates to everday living in relatively ‘modern’ times for them. I proposed a theory on the old CFI site (maybe in archives here?) regarding two such important necessary stages of early civil/post tribal evolution that used temples and sacrifice which later became the features of only religion as it has passed down to us today.
[I think the books that became the bible and most other religious scriptures or stories from ancient times had real secular roots that just devolved into religion rather than the other way around. Thus the stories were highly unlikely to be taken serious by the average person back then as literal. Telling things in story with characters were necessary for both the memory and for teaching regarding most of real facts or issues by all different people, especially where different cultures met up in trading. The use of the names of these characters also helped translate language among the distinct people from differing places, cultures, and languages.]