Their descendants probably owned the ships that sent the slaves over. They never mention the high mortality of slaves that crossed the Sahara by Islamic slavers.
But Lands founded on slavery We have China a country that was enslaved by the Manchus until ~1920 and was enslaved by different powers for nearly 2000 years. Africa which barely has any history outside of slavery , and increase in wealth starting with islams Jihad spreading and starting the slave economy not white Europeans ( Muhammed was a white middle easterner).
Their descendants probably owned the ships that sent the slaves over. They never mention the high mortality of slaves that crossed the Sahara by Islamic slavers.