Vitalik Buterin, the co-founder of Ethereum, has expressed concerns about the increasing complexity of Layer 2 scaling solutions. Layer 2 solutions are meant to improve the scalability of blockchain networks without changing the underlying Layer 1, often by offloading some data or computations off-chain. But Buterin suggests that, as these systems become more complex, they could introduce more security vulnerabilities or end-user complexity. His concerns underline the challenges involved in improving blockchain scalability, which must be balanced against the need for simplicity and security.