Why does Jack stay silent when Ralph says he’s boss?

Jack has now taken over completely. Simon and Piggy are dead and the twins, Samneric, have been taken. Ralph has no support. The boys would just jeer at him if he tried to claim leadership.

Jack gave up on being rescued and dedicated all of his efforts towards controlling the other kids. I think that when the naval officer arrived, I think Jack's world kind of crumbled around him.