Why 'Fairness by Default' Must Become a Core Blockchain Design Principle

Fairness is a protocol property. It defines the ordering and inclusion rules for state transitions. Adding it post-launch, like EIP-1559 or PBS, creates systemic fragility and fails to eliminate value extraction.

Retrofits create attack surfaces. The proposer-builder separation (PBS) model in Ethereum creates a new cartel of centralized builders, shifting rather than solving the MEV problem. This is a regulatory honeypot.

Compare Solana vs. Ethereum. Solana’s localized fee markets and single-slot finality reduce temporal arbitrage, a form of fairness-by-architecture. Ethereum’s 12-second slots are an MEV casino by design.

Evidence: Flashbots’ MEV-Boost controls >90% of Ethereum blocks, proving that retrofitted fairness concentrates power. Protocols like Anoma and Fuel bake fair ordering into their consensus layer from genesis.

Fairness is a constraint, not a feature. Protocols that treat it as an afterthought create extractive economies where value accrues to capital and infrastructure, not users. This is the root cause of MEV extraction and liquidity fragmentation across chains like Ethereum and Solana.

Fairness dictates protocol architecture. Compare order-flow auctions (OFA) on Flashbots to the intent-based design of UniswapX and CowSwap. OFA is a reactive patch; intent-based design proactively eliminates front-running by construction, making fairness the default state.

Fairness drives composability and adoption. Systems with fair ordering and credible neutrality, like Arbitrum's BoLD or Espresso's shared sequencer, become the preferred settlement layer. Developers build where user outcomes are predictable and not gamed by validators.

Evidence: The $1.2B+ in MEV extracted from Ethereum users since 2020 is a direct tax on unfair design. Protocols like Across that use optimistic verification for bridging demonstrate that security and fairness are not trade-offs but co-requirements for scaling.

Retrofitting creates systemic fragility. Adding fairness mechanisms like MEV auctions or PBS to an existing chain is a patch. It introduces new trust assumptions and attack surfaces that the core protocol cannot natively verify, as seen in the complexity of post-merge Ethereum's builder market.

Fairness competes with liveness. A chain optimized for finality and throughput, like Solana, structurally prioritizes validator speed over transaction ordering fairness. Adding fair ordering later forces a trade-off that degrades its core performance proposition.

The base layer defines incentives. If the state transition function allows frontrunning, applications like Uniswap and Aave become extractive by design. Protocol-level solutions, such as Fuel's parallel execution with strict access lists, prevent this at the VM level.

Evidence: Ethereum's attempt to retrofit PBS via proposer-builder separation creates a powerful, centralized builder cartel. This new entity now controls transaction ordering, a problem the original design did not solve.

Fairness is a performance tax. The pragmatist argues that enforcing transaction ordering or preventing MEV adds latency and reduces throughput. This view treats user experience as a secondary metric, focusing solely on raw TPS while ignoring the real cost: user churn from unpredictable failures.

Complexity shifts, it doesn't disappear. Building a 'neutral' base layer and pushing fairness to the application layer (e.g., via intent-based systems like UniswapX or CowSwap) creates a fragmented, unreliable user journey. The complexity and risk move from the protocol to the user's wallet and a maze of solvers.

The market is selecting for fairness. Protocols that internalize these concerns win. Arbitrum's time-boosting auctions and Solana's localized fee markets demonstrate that fairness mechanisms are a competitive feature, not a tax. Users and developers migrate to chains where execution is predictable.

Evidence: The rise of Flashbots SUAVE and shared sequencer projects like Astria proves the demand. These are not academic exercises; they are infrastructure bets on fairness as the default, because the alternative is a network that only serves sophisticated bots.