Explainability has become central to discussions of trustworthy and responsible intelligent systems, yet it is frequently reduced to the technical production of information about model structure, features, rules, or predictions. This critical review examines why opening a computational black box is not equivalent to producing an explanation that people can understand or use responsibly. The review synthesises conceptual, technical, human-centred, decisional, and accountability-oriented scholarship to evaluate the shift from model interpretability toward meaningful explanation. It distinguishes technical properties such as transparency, fidelity, plausibility, completeness, stability, and local or global scope from human outcomes such as comprehension, cognitive accessibility, mental-model development, decision usefulness, calibrated trust, and appropriate reliance. It further examines how explanations may produce overreliance, underreliance, automation bias, false reassurance, cognitive overload, or explanation mismatch when their content and presentation are not aligned with users, tasks, uncertainty, and decision consequences. From an accountability perspective, explanations may contribute to auditability, traceability, contestability, and recourse, but they cannot independently assign responsibility, provide institutional authority, or guarantee effective remedies. The main contribution is a human-centred critical synthesis that treats explainability as a socio-technical achievement rather than a model output. Meaningful explanation requires technical credibility, cognitive accessibility, contextual relevance, decision-sensitive evaluation, uncertainty communication, opportunities for challenge, and governance mechanisms capable of acting on explanatory evidence. The review therefore rejects universal explanation-sufficiency claims and identifies conditions under which explanations may assist understanding and responsible decision use without being treated as proof of trustworthiness, accountability, fairness, safety, or deployment readiness.
Explainable artificial intelligence is often presented as a means of making intelligent systems more understandable, trustworthy, and usable, yet explanation availability does not reliably produce adoption, appropriate reliance, accountability, or improved decisions. This realist review examines why explainable AI is adopted, ignored, rejected, discontinued, overused, underused, or misused across organizational, professional, technical, and decision settings. It applies context–mechanism–outcome reasoning to interpret how explanation design interacts with workflow integration, user and domain expertise, decision risk, organizational incentives, governance arrangements, and human-oversight conditions. The synthesis focuses on mechanisms including perceived transparency, cognitive accessibility, mental-model formation, perceived usefulness, trust calibration, accountability confidence, contestability awareness, algorithm aversion, algorithm appreciation, automation bias, and explanation overload. These mechanisms may support selective reliance and meaningful challenge, but they may also generate false reassurance, superficial compliance, defensive rejection, or uncritical dependence. The review distinguishes adoption from acceptance, trust from trustworthiness, reliance from appropriate reliance, and explanation usefulness from decision quality. It identifies plausible configurations in which professional expertise, uncertainty communication, traceability, feedback, and contestability support careful use, while poor workflow fit, limited accessibility, weak governance, and automation pressure suppress scrutiny or encourage misuse. The main contribution is a bounded realist synthesis and design agenda for evaluating explainable AI through context-sensitive human responses and decision outcomes rather than explanation availability alone. The configurations are explanatory propositions requiring human-centered, organizational, and decision-context validation; they are not universal causal laws, implementation protocols, or evidence of deployment readiness.