Integrating blockchain technology into the marketing, communication, and logistics processes of sustainable supply chains faces multidimensional barriers. This study uses a mixed-methods approach to identify, prioritize, and analyze the expert-perceived influence relationships among these barriers. Semi-structured interviews with 14 managers and experts were thematically analyzed in MAXQDA to derive the barrier criteria, weighted and structurally analyzed using the Best-Worst Method (BWM) and Fuzzy DEMATEL with judgments from 11 domain experts, re-derived from the raw questionnaire data. BWM identifies Legal and Regulatory Barriers (C1, w = 0.2225) and Economic Barriers (C5, w = 0.2110) as most critical, jointly accounting for 43.4% of the total weight; nine of eleven experts’ solutions met the CR < 0.10 threshold; the remaining two (E4 and E9) were retained rather than adjusted. Fuzzy DEMATEL classifies Economic, Legal, and Trust barriers as cause-group factors and Technological, Institutional, and Knowledge barriers as effect-group factors, with Economic Barriers showing the strongest net driving influence (D − R = +0.705). The two highest-priority barriers are also the two most upstream, and sensitivity analysis confirms the top and bottom ranks are stable. Interventions targeting cause-group barriers may generate broader system-level effects across effect-group barriers, an expectation grounded in expert-perceived influence rather than demonstrated causal evidence.