It is generally recognised that Moses is the writer of Genesis. (By that I mean he took information from other older documents and was also inspired by God).
So why did Moses put Mt Ararat as the place where the Ark became grounded – unless it was really true?
Mt Ararat was about 800 miles away from Mt Nebo (Deut 34:1) where Moses died.
Surely if the story was a myth, the Jews would have preferred Mt Nebo, or Mt Hermon a mountain close to them.
So it was most probable that Moses faithfully copied the word ‘Ararat’ from Noah’s original ship’s log.
In the volumes of the Encyclopaedia Britannica it states:
‘A Persian legend refers to Ararat as the Cradle of the human race; the Persian name for it is Koh-i-Nuh, meaning Noah’s Mountain.’