Ok so let's make a small recap of Team Dysfunctional Vs Kaguya from what we've seen so far.
So Sasuke calls Kakashi and Sakura useless and declares that the only reason he saved them is because they happened to stand next to Naruto. Then Kaguya transports Sasuke to another dimension, leaving Naruto alone against Kaguya. Naruto demonstrates that he can fight with Kaguya (granted Naruto is basically the Jinchuuriki of the Juubi, remember he has the power of 9 Tailed Beasts inside of him plus the power he received from the Sage). While Naruto fights with Kaguya; Sasuke declares that he can't do anything to escape from that dimension.
Enter Obito and Sakura who save Sasuke. Then once Sasuke is united with Naruto again, they need Kakashi and Obito to save them. While Naruto struggles to prevent Obito from dying, Sasuke charges against Kaguya and he can't even land a hit on her. Not even with his perfect Susanoo. Now enter asspull number God knows what number, and Obito uses his Kamui to go back to the real world and possess Kakashi thus resulting in Kakashi being able to use Perfect Susanoo. Might I remind you that this Susanoo is Obito's, and Obito is right now a kid.
So kid Obito can use Perfect Susanoo while everyone else needs to steal/receive power from someone to master Perfect Susanoo. Well I see no problem with that. 
Now in this chapter even though it's not much, Sakura manages to punch Kaguya. So I have to ask again, why exactly is Sasuke doing there?
What exactly is Kishi's intention in showing Sasuke in this war fighting along with everyone else? Does he want to show us that Sasuke isn't a team player? That Sasuke has no real purposes? Seriously why is he even there? Is it to show us that Naruto and Sasuke are destined to fight each other because of the Indra and Ashura nonsense? If that's so then he failed yet again, it was said that Indra was powerful on his own. Sasuke on the other hand needs other people to give him power, and he still isn't a match for his opponents. Unless his opponents decide to lose the battle on purpose.
Seriously how hard can it be to write Sasuke?