binary fission is a shorter and less complicated process of cell division compared to mitosis. What is the primary reason for this

The primary reason for this is that binary fission involves the division of a prokaryotic cell into two daughter cells, while mitosis involves the division of a eukaryotic cell into two identical daughter cells with a nucleus. Prokaryotic cells have a simpler structure without a nucleus, so the process of binary fission is simpler and requires fewer steps than mitosis.