Nobody in ancient times ever wrote down an objective account of why this or that mythological symbolism was used. We are given or can deduce associations betwee

Nobody in ancient times ever wrote down an objective account of why this or that mythological symbolism was used. We are given or can deduce associations between given mythological figures and various natural phenomena, but not why. As a result identifying reasons is always a contentious issue. Also yes snakes are used n the ways you describe, but there are plenty of origin myths around the world where snakes play no significant role. Also for example the snake in the garden of eden is playing a completely different role in the myth from the snakes in Australia. For example if the animal in Genesis that subverted Eve was a bird you wouldn't say oh look, the bird in Genesis is playing the same role as the snakes in Australia. Having said all that sure, snakes do play a prominent role in the myth cycles of many cultures and it's interesting to speculate why. Snakes evoke a visceral reaction in us, which would be easy for people to interpret as an almost magical or supernatural effect.