The Price of Interoperability: Exploring Cross-Chain Bridges and Their Economic Consequences

Modern blockchain ecosystems consist of many heterogeneous networks, creating an essential need for interoperability that allows assets to move seamlessly across chains. Cross-chain bridges serve as the primary infrastructure enabling this interoperability by executing verifiable state transitions that reallocate assets and liquidity across networks. Although prior work has focused largely on bridge design and security, the system-level and economic consequences of liquidity interoperability remain poorly understood. This paper presents a large-scale empirical measurement study of cross-chain interoperability based on a comprehensive dataset covering 20 blockchains and 16 major bridge protocols from 2022 to 2025. We model the multi-chain ecosystem as a time-varying weighted hypergraph and introduce metrics to characterize blockchain interoperability via bridges. We define two metrics of interoperability. Structural interoperability captures the connectivity implied by deployed bridge infrastructure, reflecting bridge coverage and redundancy independent of user behavior. Active interoperability captures how intensively users rely on cross-chain routing in practice, measured as realized cross-chain transfer volumes normalized by chain size. This decomposition enables analysis of infrastructure capacity and utilization as distinct dimensions. Our analysis reveals several key findings. First, the cross-chain network evolves from a sparse hub-and-spoke topology into a dense, multi-hub core dominated by EVM-compatible chains. Second, we show that cross-chain capital flows are return-chasing and cost-sensitive, whereas structural interoperability primarily serves as an enabling factor rather than a directional driver of flows. Third, we identify a growth-return paradox: while higher interoperability expands ecosystem scale, it dilutes native asset value. Fourth, we uncover an efficiency-fragility trade-off: structural interoperability acts as a load balancer that reduces average gas fees, but it also synchronizes economic cycles. Bridges transform independent networks into a tightly coupled system. Finally, we show that architectural heterogeneity across bridge designs leads to distinct economic and system-level outcomes, yielding direct implications for the design of scalable and resilient cross-chain infrastructure.