Bring back slavery

All of the great monuments of our species were made by slaves. Obviously things like the pyramids and the great empires of old. But also more subtly the great revolutions in thought and information. Einstein may have received a nobel prize for his work on the photoelectric effect but his greatest contribution to science was never monetarily rewarded.
Most of the moocs online run as non profits. Wikipedia wouldnt exist without thousands of volunteers working in the background to keep it useful. So what is this obsession with business as the panacea for all the world’s problems?