Drone-based Urban Air Mobility (UAM) shows immense potential in urban logistics and emergency response; however, evidence regarding its systemic sustainability remains fragmented. In a systematic review using the PRISMA methodology, this study analyzes 301 core articles to construct an evaluation framework spanning environmental, economic, social, and systemic effectiveness dimensions. Given technical similarities, electric Vertical Take-off and Landing (eVTOL) findings are integrated to anticipate operational challenges. Results highlight a clear consensus: drone delivery is time-efficient in high-sensitivity scenarios, though noise, equity, and safety remain critical bottlenecks. Meanwhile, deep controversies persist across some dimensions. Environmental benefits are highly context-dependent, contingent on operating models, battery life cycles, and clean energy proportions from a Life Cycle Assessment (LCA) perspective. Economically, a mismatch between high costs and low willingness to pay (WTP) necessitates optimized pricing strategies. Socially, public acceptance is sensitive to the balance between perceived benefits and risks. Furthermore, systemic effectiveness depends on the coupling between vertiports and ground infrastructure. Concluding that sustainable drone-based UAM is a multistakeholder systemic endeavor, we urge future research to prioritize LCA, pricing strategies, public acceptance surveys, and integrated air-ground coordination to resolve controversies and foster sustainable systems.

This paper examines how experts exert influence within China's one‐party system, where policymaking is ideologically disciplined and knowledge‐intensive. It combines the Functional Theory of Agency, which identifies patterns of action including accumulation of knowledge, brokerage, entrepreneurship, and leadership, with a typology of four expert configurations—near‐power, academic, market‐oriented, and Societal experts—to explain differences in institutional embeddedness and resource base. The paper argues that these configurations operate under conditions of conditional autonomy; expert influence becomes possible through alignment with the dominant discursive, temporal and institutional order of the Party‐state. Discursive gatekeeping determines which forms of expert agency become feasible and consequential under specific political conditions. This argument is illustrated using Caoyang New Village renewal project in Shanghai, a high‐salience planning case where discursive framing, safety and stability boundaries, and political timing activate and constrain expert roles. Near‐power experts perform leadership and intra‐bureau brokerage, while academic experts broker and selectively pursue entrepreneurship. Market‐oriented experts advance entrepreneurship and project‐level leadership, while Societal experts engage in brokerage and collective leadership, pursuing micro‐entrepreneurship within tacitly tolerated boundaries. The paper's contribution is to demonstrate that political control does not merely suppress expertise but differentiates and organizes expert agency into distinct, policy‐relevant forms.