The influence of social media marketing on Gen Z buying decisions tremendously soared during the past decade and that triggered the researchers across to investigate into the determinants. The research outcomes revealed that there is a closer link between credibility, trust, engagement, and electronic word-of-mouth with the purchase intentions and decisions of these consumer groups. Consequently, a question arises: does those revelations reflect genuine buying behaviour or a result of repeated use of similar research methodology in the field?

This paper presents a realist-informed integrative review of 150 peer-reviewed empirical studies published between 2010 and 2025. Unlike prior reviews, this considers studying dominant methodological patterns and explain their persistence through context-mechanism-outcome (CMO) configurations. Guided by PRISMA for selection and a structured coding framework, the review reveals that the researchers persistently chose cross-sectional surveys, convenience sampling, self-reported purchase intentions, and PLS-SEM opuses which eventually landed in mesmerizingly coherent results.

Cross-tabulations, temporal trends, and realist refinement shows these patterns are not random but structurally reinforced by publication incentives, analytical familiarity bias, and path dependence. The result is an illusion of consensus that side-lines behavioural, longitudinal, and qualitative insights.

By exposing how methodological choices actively constitute knowledge, the study clarifies the conditions shaping current evidence. Further the study proposes targeted means for journal incentives, training reforms, hybrid designs to enable more diverse, realistic, and relevant future research on Gen Z buying behaviour.