The Gods/Goddesses were giants. Some demanded human sacrifice. Why? They demanded it because they were giants with voracious appetites. When they died off and their half-breed offspring took over they continued the practice even when their size didn’t require it. Per the Book of Enoch:
And they took wives unto themselves, and everyone (respectively) chose one woman for himself, and they began to go unto them. And they taught them magical medicine, incantations, the cutting of roots, and taught them (about) plants. And the women became pregnant and gave birth to great giants whose heights were three hundred cubits. These (giants) consumed the produce of all the people until the people detested feeding them. So the giants turned against (the people) in order to eat them. And they began to sin against birds, wild beasts, reptiles, and fish. And their flesh was devoured the one by the other, and they drank blood. And then the earth brought an accusation against the oppressors. – Jame H. Charlesworth, The Old Testament Pseudepigrapha, Book of Enoch, page 16.
This is why God-Zeus-Jehovah went around the world and killed off the wicked giants. His bloodline became the bloodline of many royal houses, but unfortunately so did that of Prometheus and many other unchecked giants and their descendants.