The long-term viability of blockchain networks, which secure trillions in digital value, confronts a theoretical but escalating hazard from quantum computing. According to a report by Decrypt, Coinbase's advisory council has identified Proof-of-Stake protocols, including major chains like Ethereum and Solana, as particularly exposed to future quantum attacks. This assessment highlights a foundational risk: PoS security often relies on cryptographic signatures that advanced quantum processors could theoretically break. The warning shifts focus from abstract speculation to concrete institutional concern, implicating the core architecture of the modern crypto economy. The unresolved tension lies in the race to develop and deploy quantum-resistant cryptography before the technology that threatens it becomes a practical reality.