Baptism for the dead would cause the victim and the abuser to eventually both be in the same place, yes...
How can you say that? Jesus said, “Suffer the little children to come unto me.”
He also said, “Wo be unto those who lead the little ones astray.”
If a person is an abuser, he can be baptized if he’s dead, but he will never be in the same place as the innocent victim. God is just. Putting the victim in with the abuser is not justice for the victim.