The Future of Block Building is Permissionless Bundling

Top builders like Flashbots, beaverbuild, and rsync control >80% of Ethereum blocks. This creates a cartel with outsized MEV power and censorship capabilities.\n- Risk: Single points of failure and regulatory capture.\n- Data: Top 3 builders consistently win >80% of slots.

Protocols like SUAVE and Shutter Network are creating open markets for block construction. They separate trust by distributing tasks across a permissionless network of builders, searchers, and encryptors.\n- Benefit: Breaks the builder cartel through competitive, open auctions.\n- Benefit: Enables cross-chain MEV and privacy-preserving transactions.

User-centric intents (via UniswapX, CowSwap) shift power from builders to solvers. Solvers compete to fulfill user expressions, creating a natural market for permissionless bundling.\n- Mechanism: Solvers bundle intents and bid for inclusion.\n- Outcome: Reduces reliance on a few centralized builder black boxes.

Dominant searchers and builders like Flashbots and Jito already control >80% of Ethereum blocks. Permissionless bundling must overcome massive economies of scale and data advantages.\n- Network Effects: Existing cartels have exclusive order flow and sophisticated algorithms.\n- Capital Requirements: Competitive bidding requires $10M+ in liquid capital for top-of-block slots.

Sub-second block times on chains like Solana and Sui make permissionless, off-chain competition physically impossible for geographically distributed participants.\n- Proximity Premium: Builders must be co-located in <5ms from leaders to win.\n- Infrastructure Lock-In: This favors a few centralized, well-funded entities with elite hardware, mirroring traditional HFT.

Advanced intents and cross-domain bundles (e.g., via UniswapX, Across) create execution environments too complex for simple, permissionless solvers.\n- Solver Oligopoly: Only a handful of teams can build solvers for nested conditional logic across EVM, SVM, Move.\n- Verification Overhead: Ensuring bundle correctness before submission becomes a major computational barrier.

Compliance requirements for fiat on/off-ramps and institutional participation will force builders to implement blacklists, breaking censorship resistance.\n- OFAC Compliance: Major relay operators already censor >50% of Ethereum blocks.\n- Protocol-Level Risk: If compliance becomes a market requirement, permissionless entry is de facto banned.

Current permissionless builder experiments rely on token incentives from protocols like EigenLayer or Espresso. Sustainable economics post-subsidy are unproven.\n- Economic Viability: Can builder fees alone support a decentralized network of solvers?\n- Extractable Value: If MEV is fully democratized, the profit pool for builders shrinks, reducing security budget.

Permissionless builders relying on external data (e.g., Chainlink, Pyth) for intent resolution create a new attack surface. A malicious or compromised builder can exploit price feed latency.\n- Time-Bandit Attacks: Builders can revert and reorg based on oracle updates.\n- Data Centralization: Security collapses to the trust assumptions of a few oracle networks.

Today, a handful of builders like Flashbots and BloXroute dominate block production, creating systemic risk and rent extraction.\n- >80% of Ethereum blocks are built by 3-5 entities.\n- Creates a single point of failure for censorship resistance.\n- Extracts value from users and validators via opaque MEV.

Separate block building from proposing and open it to a competitive market. Think UniswapX for block space.\n- Any searcher can submit a bundle.\n- Open auction ensures best execution for users.\n- Proposer (validator) simply selects the highest-value, valid header.

A specialized chain for decentralized block building, acting as a universal mempool and auction house.\n- Cross-chain intent expression (like Across).\n- Encrypted mempool for transaction privacy.\n- Optimistic execution to prove bundle correctness.

Shifts complexity from the user to the network. Users submit intents, not transactions.\n- No more failed txns or frontrunning.\n- Best-price execution across all DEXs (like CowSwap).\n- Gas abstraction becomes trivial.

Builders need fast, cheap access to chain state and pending transactions to compete.\n- Requires specialized data layers (e.g., EigenDA, Celestia).\n- ~500ms latency tolerance for cross-chain arbitrage.\n- Data withholding attacks are the new frontier.

Permissionless bundling transforms MEV from a private tax into a competitive, redistributable resource.\n- Proposer rewards fund protocol treasuries or stakers.\n- Searcher competition drives efficiency to zero economic profit.\n- Censorship resistance is enforced by the market, not altruism.