Whats the difference for eating for sustenance to continue living and eating for sustenance to continue being immortal when you were born naturally as a god? i can buy gods needing ambrosia for that purpose, in fact It makes perfect sense when you mentioned it, because ambrosia literally is food of the gods. That's what the word means. Gods are naturally greater then humans, so god food thus to humans is something unimaginably precious for it giving immortality, but for the gods itself its there food, same way how we consider what we eat to be our food. But by the same token ambrosia is way more special, because it's food of the gods, thus any human attempting to eat or steal it is committing hubris and thus is dealt like that. Like what happened to Tantalus