@satsuki your reasoning is wrong in more ways than one. for one, theres the obvious fallacy that because the human species cant exist without reproduction, the purpose of mankind is to reproduce. (or is just the purpose of women to reproduce? do you believe men have a higher purpose but not women?) this is kinda like saying that because women need to eat to live, their purpose is to devote their lives to enjoying food. second, for the species to exist some women need to reproduce, not all women. third, a woman can be a mother and also other things, and she usually is.
reducing the purpose of women to gestating a fetus reduces mankind to any other animal. we have a higher purpose than merely to exist. what is necessary is not the same as the supreme good. if a woman is to serve the actualization of others, as all mankind should do, she can in ways other than motherhood. our highest virtue as a species besides knowing God is our pro-sociality.
the notion that God will "cease to exist" for us if we stop reproducing is also wrong. as long as one serves God, God provides for the rest of their needs. as long as one knows God, they know no grief. if someone knows God, why does it matter if they reproduce or not?
finally, this inserts my religion into things, but its true, so ill say it. the point of being born as a human isnt to continue the human race, an existence which is separate from God. God will continue the human race fine if He wills it, and if He doesnt will it, then theres no point in striving against His will. the point of being born as a human is to escape the cycle of death and rebirth itself by knowing God. even if the human race perishes, the chance to know God does not perish, because one will be reborn in a different suitable form. so, again, knowing God is the prime purpose of humanity. from it care for other creatures, not just selfish human perpetuation regardless of the state we exist in, proceeds.