The invention of written language in about 3200 BC, corresponds with the writing of the first books of the old Testaments.
Writing was developed about 3,200BC as you suggest, but Moses - the author of the earliest parts of the Bible - wasn't around until c.1,500 or 1,400 BC.
So a mere 1,700 or so years later.
The Bible is the only original publication still in print and used world wide.
"Original publication"?
You do realise that "The Bible" is a collection of writings and not a single piece of work? And that the various books were written, originally, from the time of Moses all the way up to past the death of Jesus - so a span of some 1,5oo years or so?
Furthermore, you seem to think that the individual books are word for word as per originally published, and haven't gone through various revisions, editing and so forth during the times until the earliest authoratitive versions upon which we base today's Bible?
For example, the Hebrew Bible is based upon The Masoretic Text, the oldest manuscripts of which are from the 9th century. Subsequent older sources, such as the Dead Sea scrolls, agree almost word for word with some of the texts of the Masoretic Text, but differ elsewhere, suggesting a history of revision.
So what do you consider an "original publication"?
The modern printing press was invented in about 1440, with the bible being the first book to be printed by the new technology. It is a unique first in terms of two zero point,s so we can extrapolate the present and the future.
Eh? So something happens to be, according to you, the oldest book still in print and used worldwide (although I am sure the Vedas is still in print, and used worldwide, and as a collection is older, given the relative youth of the New Testament of the Bible), AND was the first book to be printed on the modern printing press, this somehow enables us to extrapolate....
How, exactly?
What do you think it tells us?