> I sincerely doubt the slaves would agree with you. Just because one group was economically and societally OK with it, doesn’t make it morally OK.

That is wrong, slaves were happy to be alive instead of killed in most societies. It wasn't "slavery or freedom" it was "slavery or death" in most cases. America is an exception there, but in most areas with slavery it was done to criminals that otherwise would have gotten the death penalty.

Christianity forbade enslaving Christians, so we just killed our criminals for the past thousand years, but before Christianity we practiced slavery as punishment of crime everywhere as people thought that was better than killing them.