Blockchains face a trilemma of decentralization, security, and scalability where it is difficult to optimize all three simultaneously. Vitalik Buterin proposed that Ethereum 2.0, which is still in development, may provide a solution by allowing blockchains to have high levels of decentralization, security, and scalability. The document discusses the blockchain trilemma trade-off between these three properties and how Ethereum 2.0 aims to resolve this issue.