The Purge
Vitalik Buterin has laid out a new potential roadmap titled "The Purge," the fifth installment in Vitalik's ongoing series on Ethereum. The Purge proposes to reduce the need for permanent storage of all history for every node.
Source : eth.limo (Vitalik Buterin’s website)
Vitalik knows more about Ethereum than anyone else
Ethereum is a Layer 1 blockchain, but the father of all Layer 2, and is so complex that it is difficult to understand what is necessary and what is not for its future. Apart from Buterin, the rest of Ethereum's founders (including Dr. Gavin Wood) have gone on to form their own networks. So Ethereum only has the support of Buterin, which is also necessary for it.
The need of Purge Roadmap in Ethereum
Buterin sees the need for permanent storage of history in Ethereum's protocol as completely unnecessary in a changing environment. I have never run Ethereum on a node, so I cannot say how unnecessary history is in it, but Buterin uses Railgun (an alternative to TornadoCash). So we may assume that it will be related to privacy.