When comparing zero-knowledge proofs (ZK) and fully homomorphic encryption (FHE), the maturity gap is striking. ZK technology has reached production-grade status, powering live mainnet solutions like Polygon zkEVM, zkSync Era, and Scroll—proven at scale across multiple ZK-rollup deployments. In stark contrast, FHE remains in its infancy: most implementations are still confined to testnets and prototypes, with active development ongoing in research labs. While promising projects are pushing boundaries, FHE hasn't yet achieved the operational maturity that ZK enjoys. This gap reflects not just technical readiness but real-world deployment experience—a crucial factor for blockchain infrastructure.