I'm not that commenter but it's actually really interesting! There's a Babylonian tablet that predates Genesis by some time and has very similar instructions. A group in India actually built one following the tablet's instructions!

https://www.telegraphindia.com/7-days/the-ark-that-finkel-bu...

A key excerpt from above link:

> So was there an actual flood of biblical proportions in Babylon? Finkel believes that there was a real fear of flooding and stories of death and destruction that arose from these anxieties. 'The myth of the flood story, to build the boat, is an antidote to this very fear.'

I love rational explanations for mythology and it makes so much sense to me that periodic flooding would have been a problem since the dawn of agrarian civilization, and it makes sense that our forebears would have aspired to this idea of having the doomsday raft ready to go when the big one hits.