Polygon (MATIC) Labs has taken a strong stance against the emergence of Layer 3 chains, arguing that they offer no real benefits over existing Layer 2 solutions. In a recent blog post, the firm contends that Layer 3 chains can achieve all the benefits they hope to achieve with Layer 2s without the downsides.

Polygon's Critique of Layer 3 Chains

Polygon Labs asserts that Layer 3 chains largely serve no purpose and are just a gimmick. The firm argues that the only real benefits of Layer 3 chains accrue to the parent Layer 2, while users face the downsides of fragmentation and reliance on the Layer 2 for security and governance.

Customizability and Cost Benefits

Polygon Labs claims that Layer 2 chains built with their CDK are just as customizable as Layer 3 chains without the loss of sovereignty. They also argue that zero-knowledge-powered Layer 2 chains plugged into Polygon's AggLayer can lower fees further by aggregating proofs, negating the cost benefits of Layer 3 chains.

Interoperability and Onboarding

The firm contends that Layer 3 chains' claimed better interoperability comes at a high cost to developers and users due to extractive fees from the parent Layer 2. Polygon's AggLayer promises near-instant and atomic transactions, solving this problem.

On easier onboarding through centralized exchanges, Polygon Labs highlights that Layer 3 chains depend on the Layer 2 chain to connect to exchanges. In contrast, with an AggLayer connected chain, new Layer 2 chains can onboard users from any other exchange connected Layer 2.

Ethereum Co-founder's Perspective

Ethereum co-founder Vitalik Buterin has argued that Layer 3 chains make no sense as scaling solutions but could serve other purposes, such as data availability layers.

Implications for the Ethereum Ecosystem

The recent debates about Layer 3 chains could help users better understand how they work and their potential role in the Ethereum ecosystem. As the Ethereum roadmap becomes increasingly rollup-centric, the emergence of Layer 3 chains has sparked discussions among various stakeholders in the crypto space.