Your point is well-taken, Drewie. I too would agree that “proper” art is mythological – I just didn’t catch that question in your initial post.
My response was not intended to declare “this is the way it is,” but thinking out loud, guided by the distinction Campbell makes in Power of Myth between dreams and myth (both come from the unconscious, but one is in relation to the individual dreamer, and the other is collective, speaking to larger concerns). I did not express myself clearly, as my thoughts, like yours, were in the moment and only half-formed, and so wandered into the weeds.
Mythologies as well as art arise from the unconscious. In your first quote above from Pathways to Bliss, Campbell seems to be saying (at least to me) that all myth is proper myth; when it is teaching a practical lesson, it is not myth, but allegory.
Perhaps the emphasis should be on intention. Mythology in the embrace of ideology, for example, designed to move the populace to action to a specific end, isn’t mythology, but propaganda (the mythology of the Third Reich perhaps the clearest example . . . an attempt to stage-manage myth).
When artists tap into the collective psyche, that is indeed the stratum of myth; the artist serves as a channel for that material to surface, prompting a static response (aesthetic arrest – that “aha!”moment).
I think we’re on the same page here, or not far from it. Alas, sometimes words get in the way . . .