It's not about capability, it's about value.

Women's lives are valuable, men's are not. This has been the case across basically all societies in human history. Losing a ton of men really doesn't matter too much - especially young, family-less men.

Losing a lot of women, though, is really really bad.

One woman can have one child a year. One man can have hundreds of children a year.

This isn't sexist, it's reality. It's the rationale for male conscription and male disposability.