I don't know about everyone else, but I felt as if she didn't get a comprehensive background story like every other major villain. Perhaps it was because explaining her origins would just send the Naruto-verse into chaos (more characters like Kaguya who are just OP and could f*ck up our heroes in the blink of an eye), and it would deviate from the whole shinobi world into something more god-like, and maybe Kishimoto didn't want that so he kept it vague, but it could also have opened up soooo many opportunities for a new Naruto story. I don't know, maybe it's just I don't want Naruto to end at all... however, there were many things left unexplained with Kaguya and her two sons. Who was their dad? (maybe not that important, but still interesting to know. Or maybe the Chakra tree is their father? Weird). Where did Kaguya come from, and why did she need an army? Could it be that maybe she was protecting the world from someone even more evil than herself? Did she originally have the Byakugan and Sharingan (third eye), or was it granted by the Chakra tree? I think it would be so interesting if she actually had the Byakugan before consuming the fruit, (though this theory would not be possible as she got chakra from the tree first, I think?) because then it would show that the Byakugan is something not of this world, and I would like that because the Byakugan isn't appreciated enough, I think. If her origins were made known, would it change the Naruto-verse? I think so, and that's why it wasn't explained in detail. But you never know, with the new era series we don't know if there will be an enemy yet, so maybe some godly force will come from Kaguya's background?