Ethereum's PoS mechanism makes a 51% attack financially impractical, estimated at over $44 billion.
Bitcoin's PoW model exposes it to cheaper attacks, potentially costing only $8–10 billion, sparking security concerns.
Ethereum and Bitcoin are engaged in a security debate amidst Ethereum's efforts to assert dominance in scalability, data availability, and its monetary role.
Ethereum's move to PoS through the Merge makes it more robust against attacks, with over $44.8 billion staked, while Bitcoin faces vulnerabilities due to decreasing security funding.