Thanks for that reply. My immediate response would be to echo what you said to cardlady22:
" certainly there's a sense that the past is somehow superior in both history and myth."
Perhaps the "essential "big ideas" being poetically expressed in the usual tarot myths of origin?" are those found in many cultures across the globe about humans (starting with Kings, High Priests, Oracles & specially Chosen Ones) being descended from the Gods / God? From Jupiter / Jove / Zeus? From 'God-the-Father' / 'Mother Goddess'?
Many believe that there was, in our earliest human history, a 'lost Golden Age', when mankind 'walked in the Garden with God' & conversed with the Divine - before some tremendous, cataclysmic, cosmic catastrophe somehow spoiled things & led to mortality, disease, suffering, death, & even natural disasters.
Most cultures seem to begin with some kind of Emanationist aetiology, where we all start with a Divine spark, but then tragically everything goes awry through forces of 'evil' (like the Christian idea of the Fall).
We seem to need an explanation as to why bad things & 'evil' happen in a potentially perfect, Divine world (at least in our hopeful imaginations.) Like little children, we look around with mounting horror at this damaged world & cry "But it's NOT FAIR!" ... & seek scapegoats, or at least a supernatural explanation. It's all SO sad.
Then we invent systems galore to try to struggle back to Eden / the Golden Age (or Mummy's /Daddy's arms.)
Could that folk memory of ancient, long-held beliefs, deep in our collective unconscious, be what makes so many of us look back longingly to 'ancient wisdoms' / Atlantis myths / descent from Divinity/ies / Aliens etc?
And could that fanciful spiritual nostalgia itself be, on a macrocosmic scale, a reflection of what every human goes through from around 6 or 7 years old, when the developing self-conscious ego breaks off from the original sense of Oneness with Nature & the parents?
To me, it seems that individual developmental psychology is writ large in our cultural Myths / religions & spiritual systems, like Mystery School & magical initiations, ordinations, shamanic trainings, Kabbala, etc. And (again, I may be wrong - just my thoughts here) the Tarot development itself & the myths attached to it also express all that, in microcosm.
Growing up, as individuals & as a species, is inevitable - but so hard to do!
(Sorry to ramble. Been alone too much. I'll stop now, I promise.)