An academic paper by Michael Guren and Kim Hill gives these reasons for the division of labor between sexes
Mothers obligatorily care for infants because on-demand lactation occurs frequently throughout the day. Women would often lose prey were they to interrupt hunting pursuits to meet immediate childcare demands. Infants cry and fuss for many reasons, and failure to react to distress calls lowers infant viability. The situation is quite different for sessile-collected resources and some small vertebrates, where pursuit can be interrupted at any time without loss.- Why Do Men Hunt?
Hunting is also dangerous for infants because of long distances traveled under arduous conditions and dangers inherent in rapid burst pursuits.
Finally, successful hunting requires at least 15–20 years of experience to obtain maximum return rates.