Ethereum's Shifting Network Dynamics: Mainnet Dominance and the Future of Layer-2 Scalability

Ethereum's network has undergone a seismic transformation between 2023 and 2025, marked by a dramatic shift in transaction volumes, gas fees, and economic dynamics. While the mainnet remains the backbone of the ecosystem, Layer-2 (L2) solutions have emerged as the primary workhorses for scalability, raising critical questions about whether mainnet dominance signals a plateau in L2 adoption-or if it reflects a more nuanced evolution of Ethereum's value proposition.

The Rise of Layer-2s: Volume, Fees, and Economic Rebalancing

By mid-2025, L2 networks such as Arbitrum, Optimism, and Base were processing over 2 million transactions daily, dwarfing Ethereum's mainnet throughput of 1.7–1.8 million transactions per day. This shift was catalyzed by the Dencun upgrade in March 2024, which slashed L2 settlement costs by 90%, making these networks far more attractive for everyday use. As a result, gas fees on L2s plummeted to an average of $0.17, a stark contrast to the $100+ peaks seen during the NFT boom.

However, this growth has come at a cost for the mainnet. Daily fee revenue on Ethereum's mainnet collapsed from over $30 million pre-Dencun to just $500,000 by late 2025. Meanwhile, L2s like Base generated $94 million in fees since March 2024 while contributing only $4.9 million in blob fees to Ethereum. This imbalance has sparked debates about whether L2s are extractive or symbiotic to Ethereum's ecosystem. Critics argue that L2s are siphoning value away from the mainnet, while proponents highlight their role in enabling Ethereum to compete with high-speed blockchains like Solana and Binance Smart Chain.

Developer Migration and Ecosystem Growth

The migration of developers from the mainnet to L2s has further accelerated this shift. In 2023, zkSync Era and Arbitrum attracted significant ETH migration during their launches, with zkSync Era pulling in 7,027 ETH in its first 24 hours. By 2025, total value locked (TVL) across L2s surged from $4 billion to $49 billion, with Arbitrum capturing 44% of the market and Base at 33%. Innovations like ZK Rollups and Optimistic Rollups have not only improved transaction speeds but also enhanced privacy and user experience, making L2s the go-to infrastructure for DeFi, gaming, and social dApps.

Despite these gains, the mainnet remains indispensable for securing and finalizing L2 transactions, a role critical to maintaining Ethereum's security and decentralization. The Pectra upgrade in 2025 aimed to address the value capture imbalance by doubling blob capacity, potentially allowing the mainnet to retain a larger share of L2-generated value.

Mainnet Dominance: Plateau or Transformation?

The question of whether mainnet dominance signals a plateau in L2 adoption hinges on two factors: value settlement and ecosystem resilience. While the mainnet's fee revenue has declined, its role in finalizing L2 transactions ensures it remains the ultimate source of trust and immutability. This duality suggests that mainnet dominance is not a plateau but a strategic repositioning-where the mainnet focuses on security and settlement, while L2s handle throughput and user experience.

Moreover, the rise of ZK Rollups and modular blockchain architectures (e.g., Celestia, EigenDA) is likely to further decouple data availability from execution, enabling Ethereum to scale without sacrificing decentralization. By 2026, ZK Rollups are expected to dominate high-value transactions due to their superior privacy and finality, reinforcing the idea that L2s are not a threat to Ethereum but an extension of its vision.

Investment Implications

For investors, the key takeaway is that Ethereum's ecosystem is evolving into a multi-layered infrastructure where the mainnet and L2s coexist symbiotically. While the mainnet's economic model faces headwinds from declining gas fees, its role in securing L2s ensures long-term relevance. Meanwhile, L2s like Arbitrum and Base are generating substantial revenue and TVL, offering attractive opportunities for exposure to Ethereum's scalability narrative.

However, risks remain. If L2s continue to extract value without adequately contributing to the mainnet's security or economic model, Ethereum's deflationary narrative could weaken. Conversely, successful upgrades like Pectra and the adoption of ZK Rollups could reinvigorate the mainnet's value capture, creating a flywheel effect for the entire ecosystem.

Conclusion

Ethereum's shifting network dynamics reflect a maturing blockchain ecosystem where scalability and security are no longer mutually exclusive. Mainnet dominance is not a plateau but a strategic pivot toward a future where L2s drive adoption while the mainnet ensures trust. For investors, this evolution underscores the importance of diversifying exposure across both the mainnet and leading L2s, as the next phase of Ethereum's growth will likely be defined by their interplay.