A summary of this myth is that two gods tried to get a village to choose them with gifts. Poseidon gave them a river but it was salt water so they cant do much with that. Athena gave them an olive tree that had lots of uses. In the end the town people didn't choose. Poseidon realized his gift was not as good as Athenas so he chose for them.
They were to answer the kind of awkward questions children ask. It shows that they used to have traditional rites and customs because this was a part of their every day life. They were trying to give meaning to the world around them. They have different gods that mean different things. They made them to entertain people also.