Ethereum's Dencun Upgrade Preview: Layer2 Ecosystem Competition and Gas Fee Revolution Deep Dive

As the Ethereum network continues to face scalability bottlenecks, the eagerly anticipated Cancun-Deneb (Dencun) upgrade is on the horizon. The core proposal, EIP-4844 (Proto-Danksharding), is seen as a milestone for the Layer2 ecosystem—it introduces a new temporary data storage structure called Blob, which will significantly reduce the cost for Layer2 networks to submit transaction data to the Ethereum mainnet. On the eve of the upgrade, market discussions are intensifying around the extent of Layer2 gas fee reductions, shifts in the competitive landscape, and Ethereum's evolving narrative as the "scaling powerhouse." This article provides a forward-looking analysis of the structural changes Dencun may bring from three dimensions: technical impact, economic models, and ecosystem competition.

1. Dencun Upgrade: From "Data Storage" to "Gas Fee Revolution"

At the heart of the Ethereum Dencun upgrade is EIP-4844, which provides a dedicated data availability space—Blob—for Layer2 networks. Previously, Layer2 networks compressed transaction batches and submitted them to the Ethereum mainnet as CALLDATA, occupying expensive permanent storage. Blob data is automatically deleted after approximately 18 days, drastically reducing long-term storage costs. According to technical assessments previously shared by the Ethereum Foundation, the cost for Layer2 to submit data could drop by over 90%. While the exact reduction depends on network congestion and Blob pricing mechanisms, the market broadly expects transaction gas fees on mainstream Rollups like Arbitrum and Optimism to fall to a few cents or even lower. For end users, this means lower cross-chain transfer costs, more frequent on-chain interactions, and increased activity in high-frequency scenarios such as DeFi and gaming. Moreover, the introduction of Blobs does not increase the execution layer burden on the Ethereum mainnet; Layer2 will truly assume the "execution layer" role, while Ethereum strengthens its position as a "decentralized settlement layer."

2. Layer2 Economic Models: From "Burning Cash" to "Profitability"

Under the current architecture, Layer2 projects pay substantial CALLDATA fees to the Ethereum mainnet, leading to high operational costs. For example, Arbitrum reportedly spent millions of dollars monthly on data submission to Ethereum. After the Dencun upgrade, Blob fees will be significantly lower than CALLDATA, greatly improving the cost structure for Layer2 operators. This will have two direct impacts: First, Layer2 projects will have more incentive to reduce user transaction fees, potentially even launching zero-gas promotions; second, projects can redirect saved operational funds toward ecosystem incentives, developer subsidies, or treasury reserves, accelerating network effects. Additionally, the introduction of Blob data alters Layer2 staking and verification mechanisms—re-staking protocols like EigenLayer may leverage Blob space for additional economic security. However, it's important to note that Blob storage also has a dynamic pricing mechanism; when multiple Layer2 networks submit large amounts of data simultaneously, Blob fees will rise accordingly, so gas fee reductions are not linear or infinitely approaching zero.

3. Ecosystem Competition Landscape: Arbitrum vs. Optimism vs. zkSync

Arbitrum: First-Mover Advantage and Ecosystem Depth

Arbitrum, with its full EVM compatibility and early mainnet launch, has long held the top spot in Layer2 Total Value Locked (TVL). According to data platforms like L2BEAT, its TVL share exceeded 50% in early 2024. Post-Dencun, Arbitrum's per-transaction gas fee is expected to drop from around $0.1 to the $0.005 range, significantly boosting on-chain activity. Leading protocols in the Arbitrum ecosystem, such as Uniswap, GMX, and Curve, have already accumulated substantial liquidity, and lower gas fees are likely to attract more long-tail assets and retail users. Meanwhile, Arbitrum is advancing its Stylus-based contract upgrade, allowing developers to deploy smart contracts using languages like Rust and C++, further lowering the development barrier.

Optimism: OP Stack and the Superchain Narrative

Optimism's bet on the OP Stack toolchain enables any project to build custom OP Rollup sub-chains while sharing Ethereum's security—this "Superchain" vision aims to unify multiple Layer2 networks under a common interoperability standard. After Dencun, the cost of deploying and operating OP Stack sub-chains will also decrease, making building a new Rollup as cheap as deploying a smart contract. As of the upgrade's eve, notable projects like Base and Mantle have already launched or tested on OP Stack. Optimism is creating an "Internet of Layer2 ecosystems" through shared sequencers and cross-chain messaging protocols. Its token, OP, plays a central role in governance and incentives, and ecosystem expansion could provide new scenarios for token value capture.

zkSync: ZK-Rollup's Catch-Up and Differentiation

zkSync Era, centered on zero-knowledge proofs, surpassed StarkNet in the second half of 2023 to become the leading ZK-Rollup. ZK-Rollups theoretically offer faster finality and stronger privacy potential. While the Dencun upgrade primarily benefits Optimistic Rollups (by reducing data submission costs), ZK-Rollups also benefit from cheaper Blob space. The zkSync team plans to launch seamless cross-chain bridges and native account abstraction post-upgrade, further improving user experience. However, zkSync's ecosystem scale still lags behind Arbitrum, with TVL roughly one-third of its rival. Dencun could be a window for the ZK camp to accelerate its catch-up—if gas fees become nearly negligible, users will focus more on transaction speed and security, and ZK-Rollup's instant finality will offer a differentiating appeal.

4. Potential Challenges and Risks

The Dencun upgrade is not without concerns. First, the stability of the Blob pricing mechanism remains to be tested by the market: if many Layer2 networks submit data simultaneously, rising Blob fees could lead to smaller-than-expected gas fee reductions. Second, the revenue structure for Ethereum mainnet miners (validators) will change—Blob fees will partially replace CALLDATA income, but overall gas fee revenue may face short-term pressure. Third, interoperability among Layer2 networks remains fragmented; users must bridge assets across different networks, and while lower gas fees reduce friction, the risk of security incidents (e.g., bridge exploits) persists. Fourth, from a regulatory perspective: as Layer2 transaction costs drop significantly, the barrier to entry for decentralized applications lowers, potentially drawing increased attention from regulators regarding on-chain activity compliance.

5. Ecosystem Impact and Future Outlook

The deeper significance of the Dencun upgrade is that it officially kicks off Ethereum's "Layer2-centric" scaling roadmap. Vitalik Buterin has repeatedly stated that Ethereum's core function in the future will be as a decentralized data availability and consensus layer, with the vast majority of transactions and computation handled by Layer2. Post-upgrade, competition among Layer2 networks will shift from "who survives" to "who offers the best user experience and richest application ecosystem." For ordinary users, the most immediate change is that on-chain costs for using Uniswap, lending protocols, or even minting NFTs will drop significantly—from several dollars to just a few cents or less. This will encourage more Web2 users to try on-chain applications, driving the next wave of user growth.

At the same time, Dencun lays the foundation for Ethereum's future sharding expansion (e.g., Danksharding). The number of Blobs will gradually increase, from an initial 4 per block to 64 or more in the future. At that point, Ethereum will truly have the capacity to handle global transaction volumes. However, in the short term, whether Dencun triggers a price rally for Layer2 tokens remains uncertain, as the market has partially priced in the upgrade. For projects and investors, the focus should be on the actual increase in ecosystem activity post-upgrade and the emergence of new applications.

6. Risk Disclaimer

Risk Disclaimer: This article is for industry analysis and research sharing only and does not constitute any investment or financial advice. The cryptocurrency market is highly volatile, and the development of Layer2 projects may be affected by multiple factors including technical failures, regulatory policy changes, and market sentiment fluctuations. Investors should fully understand the relevant risks and participate cautiously based on their own risk tolerance. Data sources mentioned in this article are from public channels; specific figures may change over time, so please refer to the latest data.