Explain the Concept of “Economic Finality” in a PoS Blockchain

Economic finality means that a transaction is irreversible because reversing it would require an economically prohibitive cost. In Ethereum PoS, this is achieved when a block is attested to by two-thirds of the total staked ETH.

Once finalized, the only way to reverse the transaction is to slash the entire stake of those two-thirds of validators. This high cost makes reversal economically infeasible and ensures chain integrity.