There was no slavery in Kemet (Ancient Egypt). That's a Biblical narrative. The writings from Kemet itself has records of bartered exchange in which workers, priests, artists, etc. were paid in housing, medicine, food, and even beer (which was a source of antibiotics). We know this because the world's oldest recorded labor strike is a New Kingdom document under Ramses III with a threat of workers raiding tombs for the grains/millet and other food stocks because supplies were being set abroad for soldiers instead of working at home.

Moreover, the overall premise of this is flawed in that the trade of glass beads/woven cloth that led to slavery is marginal compared to warfare waged by competing European powers to raid African villages, often with help from other African ethnic groups, to capture and enslave Africans. The 1944 book "Capitalism & Slavery" by Eric Williams is still in circulation with more contemporary introductions and specifically explains how enslavement funded the Britain's Industrial Revolution and led to the establishment of Central Banking. But even before banking, Lords of London and others were insuring ships of enslaved African who were mostly forcibly acquired than bad trade deals because Africa proper was being destabilized. What Europe had was better weaponry fueled by the myth of Black inferiority and dehumanization through Hamitic myth tales. So some points are just wrong - the Ancient Egyptian portion - and others in terms of the beads/cloths are slices of a larger pie of the historical narrative that involved warfare.