truth_b_known , I used Conan and his god Crom in an argument on the evolution of deities with a JW relative.
The key quote is when Subatai says to Conan: "My god is the eternal sky... your god lives beneath my god."
That's all it is: The gods are just different societies playing god top trumps over time. That's why pantheons haven't survived, one god that can do everything that the individuals of a pantheon can do is stronger, more impressive.
This also explains why gods become less directly involved over time and more remote and enigmatic.
Ok, that's my theory. Now maybe someone who knows their stuff can tear it apart? :)