The Hero's Journey suggests otherwise.
In other words they're sort of like a cultural Rosetta Stone that lets you interpret and understand totally alien cultures or understand nuance in ones that you are already versed in so that you can have a better understanding of them.
The link that you provided has a quote from Campbell himself pointing out the impact different religions have on the stories that the people in those cultures tell:
> One finds different orders of story. For example, in fairy tales it’s usually the finding of the bride — or sometimes stealing the bride — and the sacred marriage motif. In the Roman Catholic tradition, it’s the atonement with the father motif — and there the woman becomes either the guide to the father in the form of Mary, or seductress in the form of Eve and her children. In the Christian tradition one is not to experience the apotheosis. You are not to think of yourself as the Christ, whereas in the Buddhist tradition that’s the way.
An interesting thought that just struck me is how something like Campbell's work (and the work of Joyce that inspired it) has impacted the crafting of fictional narratives going forward, with his research and analysis perhaps permanently changing fiction because of the meta-awareness of story telling that it imbues on storytellers. Another way to look at that is that Campbell's work is like a sort of atom-bomb on the creation of cultural artifacts with ones being made prior to it becoming like a sort of 'low-background steel' and ones that come after it being markedly different simply because of the existence of the publishing of his research.
> Science fiction is an existential metaphor that allows us to tell stories about the human condition. Isaac Asimov once said, "Individual science fiction stories may seem as trivial as ever to the blinded critics and philosophers of today, but the core of science fiction, its essence, has become crucial to our salvation, if we are to be saved at all."