“HAVE THEY PROVED THAT MAN HAS NOT BEEN HERE FOR 6000 YEARS?”
That is specific to Protestant/Reformation Christian sects. Persons belonging to such sects are obsessed with their chosen structured belief system's scientifically inaccurate narrative that modern humans have only walked the earth for 6,000 years because a literal (Sola Scriptura) reading of Genesis says so.
"What does it matter?" is a question. Not an answer. An example of a decent answer would be "The builders of Göbeklitepe would have the answer to your question."