The incongruity between South Asia's economic growth and extreme poverty has led to a growing interest in social protection and subsequent implementation of anti-poverty initiatives. However, many programs have consistently fallen short of their full potential in reaching the poor. We reviewed the literature to understand the factors behind this failure. A search of EconLit, Global Health Database, MEDLINE and SocINDEX, supplemented by an external search, yielded 42 papers evaluating 23 programs. Inclusion criteria included social and political determinants of program outcomes. Articles were assessed for quality using the GRADE and GRADE CERQual criteria and analyzed using Thomas & Harding's thematic synthesis approach. We identified five themes: (1) structurally flawed program theories overlook the complexities of poverty and are rooted in simplistic cause-and-effect approaches; (2) elite capture through appropriation of benefits, powerful positioning in program implementation, and gatekeeping through relationships of patronage; (3) insufficient targeting strategies to reach the poorest; (4) neglect of gendered restrictions, hidden costs, lack of legal documentation, and physical and social exclusion; (5) active self-exclusion from social protection to maintain dignity, a perception that programs are substandard, and a lack of resources required. The review highlights the well-documented disconnect between South Asian social protection program designs and the ground realities of their 'ideal' beneficiaries. This stems from a dominance of Western-led poverty discourse that disregards the influence of caste, the challenge of effective engagement with a group whose identity remains unclear, and fast-paced funding calls that do not lend themselves to meaningful identification and collaboration with the invisible poor. We suggest this disconnect is intentional and reflects a broader power dynamic rooted in geopolitical interests and national priorities. Study limitations reflect the shortcomings of the existing literature, which largely uses quantitative research methods that fail to capture the multidimensional experiences of the poor.