Legacy does not mean only good.
When people talk about leaving a legacy behind, they mean leaving behind something that will contribute positively to the planet and/or benefit the creation.
I would say both genders ultimately have very similar if not the same biological and societal aspirations. Namely they want wealth, and legacy.
Yes this comes from lower sensual desires or our animal instinct.
Man and woman are not the same biologically. One man can have over 1000 children. The same can not be said of a woman, at least we haven't seen such a thing happen in human history yet. It also seems one sex is dominant in this declining birthrates fearmongering narratives. It is absurd to the point some men even believe they are fulfilling their "purpose" by aspiring to impregnate as many women as they can in their lifetime, no mention on how they plan to be involved in their children's lives. All I am saying is, if any male here believes this lie, there's no need to have alot of children in this day and age to leave a legacy behind. There are many ways one can leave a positive mark and having children is not a guarantee of "good" legacy.
True God deeds can come from other means like beneficial institutions of knowledge and sadaqah Jariyah.
Might be difficult but not impossible. The consciousness of the people that form society is ultimately the driving factor.
Look at how China took hundreds of millions out of poverty and built a futuristic, clean and well organized society. They might not have done it in the ideal way, but nevertheless.
We have different ideas of what constitutes a successful society.
China's creation of an artificial world is hardly a success. We see the effects of overpopulation and competition when teenagers and young adults are jumping from highrise buildings. Yes, they tried finding "solutions" and now it looks all prim and proper on the outisde but what is the mental, spiritual and physical state of these people?
That is a western secular way of looking at things. When in their higher benevolent consciousness, human beings are the vicegerent of God.
For a higher benevolent conscious beings, we sure behave worse than animals. You will never see lions wipe out a whole population of antelopes for profit. They will kill when they are hungry, taking only what they need.
Advocating for a responsible way to live harmoniously with fellow humans and non-human beings was dominant in eastern teachings before it got adopted by the western scientific world. If you are familiar with the concept of tragedy of the commons, China's environmental pollution can cause beach critters in Somalia to lose their habitats. Why? Because we are all interconnected and share one planet.