An excellent article explains the importance of Ethereum's dynamic availability consensus mechanism, which provides both economic finality and ensures the blockchain continues to function even if economic finality cannot be achieved. Once @leanethereum is fully deployed, Ethereum will become the only mainstream blockchain to possess both of the following: (i) theoretically optimal security under synchronous conditions (requiring 51% honesty of online validators); and (ii) strong economic finality under asynchronous conditions. Most "semi-centralized fast chains" only choose (ii), PoW chains only choose (i), while Ethereum possesses both.