>>512960174
It still is the child thing. You can easily kill off 1/3rd of the male population and don't see any sizeable decrease in births as the birth rate of women does not correlate with how many men there are in society but only how many women. See graph attached - you kill one third of all men and still only see a 10 percent reduction in the birth rate. This is why you do not draft women, even if you do not like this answer.

Also, women are weaker, less ruthless, more prone to injury, cannot endure war like men psychologically and do not follow orders at the front. So drafting women is an absolute last option only employed as a measure of last resort (e.g. Soviet Union in ww2 for snippers or Germany in 1945 but only last days).