it is an objective requirement.
as a species we objectively NEED to survive, its about the only objective truth we have. it is what has driven us, and our evolution. the fact that society has developed in a way to get away from the objective need aspect, doesn't actually invalidate it. and just because the subjective wants in society are different than the objective needs doesn't change the objective needs of our species.
so in order to survive our species needed to evolve to be able to determine which of our potential partners made the best mate that gave the best chance of their combined offspring to survive.
breasts, hips, vaginas, and periods have all evolved with us as a species as outward facing identifiers that this woman can probably bear healthy children. we as a species objectively needed that information. there are several periods where our ancestors got down to the several thousands numbers after various disasters. we NEEDED to know who was healthy long before health care was around to tell us. if we didn't have those identifiers, bigger breasts and hips, at those critical times in our history it is very likely we are extinct today.
it is quite literally an objective need in human history to know who we should breed with. it still is today. like if dudes just started banging no one but people incapable of bearing children, we would go extinct. that's not a subjective opinion, its a cold hard basic fact of life.
and its playing out in modern society. birth rates have PLUMMETTED in the developing world which has created huge economic and societal issues. child birth and the ability to raise those children is literally the most important thing to our species. not sure how you can call it subjective.