I have long predicted that if science comes up with an easy, safe, birth control for men that they WIDELY adopt, including teen males, then it will lead to a change in female behavior as their sex instinctually fights to regain control over sex, a return to sexual restraint and holding out for commitment.
Without the threat of pregnancy, then modern American men are living in a sexual, all you can eat candy store, biology won’t allow women to put up with that for long, nature will steer them into a counter strategy.
Falling birth rates, whatever the reason, herald the collapse of a society.