Beyond IoT: AGI as a Transformative Solution for the Internet of Everything and Relationship Explosion

This review explores the evolution from Internet of Things (IoT) to the Internet of Everything (IoX) within the cyber-physical-social-thinking (CPST) hyperspace, centering on the emerging challenge of 'relationship explosion.' As interconnected systems grow in scale and complexity, the exponential proliferation of internal (e.g., device coordination and data aggregation) and cross-space (e.g., streaming, translating, and adapting) relationships leads to scalability, security, and real-time processing challenges. Through a systematic literature review (SLR) guided by five research questions (RQs), we analyze how this relational explosion intensifies across IoX domains - spanning IoT, Internet of People (IoP), and Internet of Thinking (IoTk) - and undermines the efficacy of artificial narrow intelligence (ANI) in managing dynamic, heterogeneous environments. This review proposes that artificial general intelligence (AGI) offers a transformative solution, enabling adaptive reasoning, cognitive firewalls, and unified decision-making to navigate complex relationship networks. AGI-driven methodologies enhance system resilience, security, and efficiency in aggregating, moderating, and evolving relationships across CPST spaces. The article outlines a classification of relationship types, evaluates AGI's advantages over ANI, and proposes a future research roadmap emphasizing ethical governance, human-AGI collaboration, and sustainable architectures. By framing IoX development around the management of relationship explosion, we provide a roadmap for future research, emphasizing interdisciplinary efforts, ethical governance, and sustainable frameworks to foster intelligent, socially aware IoX ecosystems.