It makes logical sense to have gender roles. Just to survive means females between teens and mid forties need to be pregnant or nursing a baby. Both those will limit hunting, thus making gathering the better role. Of course died in childbirth is likely .

Note that the above does not preclude women hunting. It limits them to less active roles at times, but different stages of child bearing will put different limits on ranging from full abilities to practically a cripple. Also hunting takes different forms, and some are more amenable to help than others.

We also know men would gather at times.