People today forget the application of slavery was a merciful response to the people starving to death in Egypt. They had nothing else to exchange for food.
People do not want to recognize that slavery is an economic system that still works to this day, even if we are appalled by it. In the movie The Sound of Freedom it explains how child slavery is the fastest growing business in the world, on pace to overcome the illicit drug trade. No respectable person claims slavery today is voluntary like the origins of slavery in the Bible.
I just wanted to point out that slavery is a time tested economic system. The reason it was abolished was NOT because people in the 19th century suddenly got a moral conscious. The reason slavery was abolished is because of the invention of Capitalism and the Industrial Revolution; a free person with an economic motive outproduces a slave. There is no obvious Scriptural condemnation against it.
In fact, the Bible was used to justify slavery, even though it does not a command to enslave but only mentions it as dicta. The Bible makes no moral stand either way. In Philemon Paul implies the slave should be treated well because he turned to Christ, not set free on the moral grounds that slavery, itself, is morally wrong. No one should confuse the Bible ACCEPTING the existence of slavery with APPROVING IT.
Slavery is an economic system that passed the test of time for one reason; it works. Thank God we are free in Christ.
Sorry you misunderstand what the bible and history teaches.
In the old testament the poor or indebted could sell themselves or family members into a limited form of slavery.
It was never intended to be life long, but was as you've said a form of poor relief.
It like all systems got abused and mishandled, read the prophets rebukes to Israel about the treatment of the poor.
Slavery, chattel slavery for life was permitted as a result of war, but the kidnapping of people in order to sell them as slaves has always been forbidden.
Look at the lists Paul gives of those who will not be admitted into heaven, slave dealers see 1Tim1:10
You yourself admit that slavery today is profitable just as it has always been profitable through history.
It was not changing economics that did away with slavery in the developed world but Christian action through legal means.