Board Thread:Theories and Speculation/@comment-46001698-20200605061506/@comment-11830817-20200605063144

Obito did not have access to susanoo while he was alive. As to why Sasuke didn’t, we do not know. Maybe he was not fast enough, or maybe he knew it would not work. Considering Kaguya’s hair needles were able to penetrate Sasuke’s susanoo, I would wager that the All-killing Ash bones would be able to as well.