I would rather ask another question to spice the discussion:
Why Do People Want Kaguya to Use Shinra Tensei and Other Six Paths Techs?
Well, I see their Reasons,
they think the dumb eye Kaguya has is a Rinnegan. Sometimes, they even think that dumb eye is the father of all the dojutsus in the Narutoverse. Unfortunately, they are wrong. That eye is not the father of the Byakugan, and it is too weak to be the father of the purple Rinnegan of Hagoromo.
In fact, so far, I have noticed that Kaguya's eye is a big Sharingan, nothing else. It makes dimensions just like Obito's Sharingan, and can teleport people in any of her own dimension just like Obito.
On the other hand, I bet that the purple Rinnegan can do everything that dumb eye does + the six paths techniques. The reason I know that is an hint from Nagato. When Nagato learned that Naruto was in Mount Byokuzan, he destroyed the village, and was about to go to capture Naruto. Basically, if Naruto did not come, nagato would have gone to the toadland without having any contract with them. This tells me that the person who has Hagoromo's Rinnegan is actually above everything in the Narutoverse - pretty much the Narutogod.