South Korea confronts an unprecedented demographic crisis, with its total fertility rate (TFR) plummeting to 0.72 in 2023, the lowest in recorded global history. Despite substantial government investment exceeding 280 trillion won since 2006, conventional pronatalist policies have failed to reverse fertility decline. This study employs McDonald’s gender equity theory and the Second Demographic Transition framework to analyze the structural causes of policy ineffectiveness, demonstrating that ultra-low fertility persists due to institutional incoherence between individual-oriented and family-oriented gender equity. Through comparative analysis of six countries (South Korea, Sweden, France, Japan, Singapore, and Taiwan), this research reveals that effective fertility policy requires comprehensive institutional transformation rather than financial incentives alone. The findings indicate that South Korea’s failure stems from treating fertility as a resource shortage problem rather than addressing fundamental institutional gender inequities embedded in labor markets, workplace cultures, and family structures. This study provides evidence-based policy recommendations emphasizing institutional coherence, gender equity in both individual and family domains, workplace flexibility, affordable childcare infrastructure, and cultural transformation away from intensive mothering norms.