If you must know then I will tell you...
The ten tails is a sentient being. It is attempting to escape the samsara via evolution. It is using the inhabitants of the planet as vessels to create a gene pool that would allow for its max potential to be manifested. We know about the chakra fruit and the Otsutsuki influence on shinobi.
I think there is another race of beings that inhabit the Narutoverse. My suspicion is that they are from the underground system of caverns near ryuchi cave. They used the chakra tree for nourishment and became something not human. They are trolls. Yes trolls inhabit the Narutoverse. I don't want to say too much because it would spoil the plot but don't be surprised if there is a troll arc in Boruto
