The demographic shock of the medieval plagues made people more visibly valuable as labor, military manpower, and potential ransom. Prisoners had been taken earlier, but larger-scale capture became more common afterward. Professional sailors and pirates had added reasons to keep captives alive because they understood the sea's dangers and depended on continued commerce. Nobles without the same commercial incentives could be more willing to destroy captured crews.
Notable Point · 2:07:22-2:08:12
How plague-era demography changed the value of prisoners
Large-scale prisoner taking became more common after the plagues as human labor and military skill grew scarcer.