Yet jws and many other others including muslims, jews, and sundry
christians believe that their fanciful religious fantasy is true in the
face of factual evidence to the contrary
There are plenty of indicators of those ages existing. Something I find interesting is that the Bible itself doesn't establish any timelines in terms of the stages in which things on Earth came to be. It is based on interpretations of writings that are considered sacred.
As per Jesus of Nazareth, he did exist. That he is what the Bible and religion claims he is, that's a different story.