Sasuke is a necessary counterpart to Naruto in This Manga.
The story needs an Uchiha if it's going to conclude the cycle of hatred that began between the Younger and older brother sons of the SO6P, or Madara and Hashirama. I think it's obvious that Sasuke needs to be developed to the point where he can play his role.
while you are right, it doesnt improve the quality of the manga and as of late they have been so boring.
It can get even deeper; what if Itachi's father told, commanded, or wanted Itachi to eventually sacrifice Sasuke for his eyes and gain the EMS as a weapon against Konoha. Or something along those lines! O_O
@S.I.M.S., you have made a very good point. I think Itachi is keeping a dark secret from Sasuke, the reason this seems more likely to be the scenerio to me because Sasuke's father never gave a crap about him. It was all about Itachi.
How long will it take for Itachi to force Kabuto to Undo Edo Tensei?
Could it be that with the final effect of Izanami, Kabuto would learn from the mistakes he made in the past and take a different path. As what I've understood, you can only break from Izanami by going through some kind of self-realization. So when Itachi said, it's time to end Edo Tensie, probably Kabuto will wake up from Izanami a changed person and voluntarily end edo tensie.
This is my prediction. Now that Kabuto is under an illusion. Madara can now freely detect his location and immediately transport there via zetsu-like transportation and kill Kabuto even before he can end ET.