Sagas are technically poetry, but, they are not at all in the same family as what most think of poetry today.
Discussion
Aristotle wrote The Poetics.
Yes.
But that's not the same thing as oral history preserved in a very specific format that allows for easier rote memorization. It's poetry with a purpose. It's not the same thing as the weirdo ee Cummings or the flowery blech of Yates.
(I hate most poetry, so my bias is showing. I'll shut up now.)