Sure it is real, but it only takes a short while to throw it up. And so what? Why did they stop there - in that particular spot and not some where else? etc - unknowable, unanswerable - questions abound - each taken alone, developed in isolation to fit a preconceived theory. None fitting a whole - remember the great ice age had only ended several thousand years earlier — what was lost as the sea rose hundreds of feet virtually over night, as the land echoed with huge earthquakes when the long depressed land rebounded?
There is more to “prehistory” that we imagine, and maybe more then we can imagine...
There is example after example of things which could have existed, but because of the catastrophes from Mt. Toba in 74,000 BC to the melt beginning in 16500 BC nothing remains.
Nothing except the orts and other dentris on which some get money by pointing out, but signifying nothing.