I never claimed morality is objective.
They do not "objectively" or inherently allow anyone to live better. The Spartans, for example, made it a regular practice of killing slaves to keep their numbers down. It was considered moral, even necessary, by the Spartans, but this obviously did not make life easier for their slaves. Many Christians believe it is their religious moral right to discriminate against certain groups of people, and it isn't making life easier for those groups.
The American state of Missouri used to have a law that made it legal to kill Mormons and drive them out of the state. There was also the treatment of the native Americans, which did include, among other things, rape and murder.
I stated such earlier in the thread.