Why the Holocaust in Europe?

Advanced technology cannot explain it, for far lesser civilizations such as Cambodia, pre-industrial China, and the many Bantustans of Africa prove that nothing more than a machete, or a pistol, or indifference are required for mass murder. However, it can explain how Nazi Germany could kill off ~11 million people in six years, in multiple countries in Europe and North Africa, while fighting wars on two fronts against industrialized world powers. Without their technological advancement and smoothly functioning bureaucracy, the pace and extent of the slaughter could not have been possible.