ChainCatcher message, Ethereum co-founder Vitalik Buterin published a new article titled "The Future Development of the Ethereum Protocol (Part Five): The Purge." The article states that one of the challenges facing Ethereum is that, by default, the expansion and complexity of any blockchain protocol tend to grow over time. This occurs in two areas: historical data and protocol features.To ensure the long-term sustainability of Ethereum, strong counter-pressure needs to be applied to both trends, reducing complexity and bloat over time. At the same time, one of the great features of blockchain needs to be preserved: permanence.The key goal of The Purge is to reduce the storage requirements for clients by decreasing or eliminating the need for each node to permanently store all historical records, and possibly even declaring them obsolete; and to lower protocol complexity by eliminating unnecessary features.