The evolution of the Ethereum protocol through downgrade: Vitalik Buterin's simplification strategy

On January 18th, Vitalik Buterin posted a message on the X platform outlining the core issues of the Ethereum protocol. He argued that no matter how technically advanced a design is, excessive complexity can undermine fundamental principles such as trustworthiness, autonomy, and security. This statement, reported by PANews, raises important questions about the future direction of Ethereum development.

The Complexity of the Ethereum Protocol: Why Simplification Is Necessary

Vitalik Buterin emphasized that “trustlessness,” “skipping tests,” and “self-sovereignty” are three critical characteristics of the protocol. However, currently, Ethereum faces challenges in maintaining these core principles.

With hundreds of thousands of nodes operating, a Byzantine fault tolerance rate reaching 49%, and all nodes verifying through quantum-resistant cryptography technologies like PeerD and Stark, the problem lies in complexity. If the system is a tangled structure of hundreds of thousands of lines of code and cryptographic techniques at a PhD level, it will ultimately fail trustworthiness tests.

Relying on a small group of experts creates a situation that threatens a truly trustless system. The “job change test” issue also arises—if the core development team is replaced, maintaining the same quality level becomes difficult. Even the most talented developers cannot fully grasp and manage an overly complex structure.

The Vicious Cycle of Protocol Bloat: Adding vs. Modifying

The fundamental problem in Ethereum development is the process of adding features. To meet specific requirements, new functionalities are rapidly integrated, causing the protocol to become increasingly complex, with new interaction elements or advanced cryptography becoming core dependencies.

While this may help expand functionality in the short term, it undermines autonomy and hampers the construction of a truly decentralized structure that can last for centuries. The core issue is that, driven by the desire to maintain backward compatibility, additions far outnumber modifications. As a result, over time, the protocol inevitably becomes bloated.

Three Strategies for Garbage Collection

To address this issue, Vitalik proposed that Ethereum development must incorporate clear “simplification” or “garbage collection” features.

Three criteria for simplification:

First, minimize the total lines of code in the protocol. Second, eliminate unnecessary dependencies on fundamentally complex technical components. Third, add more immutable properties to clearly define the core trust attributes of the protocol.

For example, EIP-6780 removed its self-destruct feature and limited the maximum number of storage slots that can be changed per block, greatly simplifying client development.

Garbage collection can be implemented in two ways:

A partial approach involves redesigning existing features to be more concise and logical. A large-scale example is the “Merge” upgrade, which completely replaced proof-of-work (PoW) with proof-of-stake (PoS).

Managing Backward Compatibility Through Downgrades

A more innovative approach is the “Zerota-style backward compatibility.” This method involves removing complex but infrequently used features from the core protocol and downgrading them into smart contract code. This relieves new client developers from having to handle these features directly.

In practice, after a full upgrade to native account abstraction, all previous transaction types may no longer be considered essential features. Pre-compiled code can be downgraded into EVM or RISC-V code, and ultimately, the virtual machine itself could be switched from EVM to RISC-V.

The key to this downgrade strategy is to eliminate complexity while maintaining compatibility with existing features. Ultimately, the goal is to free client developers from needing to handle legacy code from older Ethereum versions.

Recommendations for Ethereum’s Long-term Sustainability

Vitalik Buterin’s recent remarks go beyond technical critique—they highlight a crucial issue shaping Ethereum’s future. Long-term, the pace of change should be slowed, and unnecessary complexity must not hinder protocol evolution.

Through genuine downgrades and garbage collection, Ethereum can evolve into a simpler, more transparent, and more trustworthy protocol. This effort aligns with Bitcoin’s pursuit of immutability and simplicity. How actively these simplification and downgrade strategies are incorporated into Ethereum’s future roadmap will play a vital role in achieving true decentralization and autonomy in blockchain.