Why Vitalik Buterin Says L2s Won’t Scale Ethereum Anymore

Buterin argued that many Layer 2 systems no longer meaningfully inherit Ethereum security.

Ethereum co-founder Vitalik Buterin said that recent developments mean that the original conception of Layer 2 scaling within the ETH ecosystem is no longer viable.

He said progress on many L2 networks is lagging behind previous expectations, while the mainnet continues to scale immediately.

Slow progress, low costs

In a recent post on X, Buterin be two important realities that are reshaping the debate. First, there is the slow and arduous progress of L2s towards decentralization and interoperability in ‘Phase 2’, and the fact that Ethereum’s mainnet has already reached very low fees, with gas limits expected to rise significantly until 2026.

Buterin reiterated that Ethereum scaling was originally defined as expanding block space that completely adopts Ethereum’s security. This means that all activities remain valid and censorship-resistant as long as the network is active. As such, systems that rely on multisig bridges or other forms of discretionary control cannot be considered extensions of Ethereum in this sense, even if they provide high throughput.

The co-founder explained that this framing no longer holds up because the blockchain no longer needs L2s to function as branded shards, while many L2s are unable or unwilling to meet the security and governance requirements such a role would imply.

Buterin noted that some projects have explicitly stated that they may never progress beyond Phase 1, not only because of technical concerns around zero-knowledge EVM safety, but also because regulations or customer requirements require ultimate control. While he said this may be appropriate for the use cases of these projects, it means they should not be described as scaling Ethereum according to the original definition.

Instead, Buterin proposed abandoning the idea that all Layer 2s should fall into the same category and be judged by the same criteria. He suggested thinking of them as a broad spectrum of systems with varying degrees of connection to Ethereum. In this context, some L2s may be fully supported by Ethereum security, while others operate with more limited guarantees. This allows users and applications to choose according to their needs.

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He added that L2s should focus on providing differentiated value beyond generic scaling, such as specialized virtual machines, application-specific efficiency, extreme throughput, non-financial use cases, low-latency sequencing, or integrated services such as oracles or dispute resolution. For networks handling assets issued by ETH or Ethereum, he said reaching at least Phase 1 should be a minimum standard.

Precompile ZK-EVM

From an Ethereum perspective, Buterin says he has become increasingly convinced of the importance of a native rollup precompile that would verify ZK-EVM proofs as part of Ethereum itself. Such a system enables reliable interoperability and composability, while L2s provides flexibility in expanding functionality.

He said that while a permissionless ecosystem will inevitably include systems with weaker or trust-dependent guarantees, it is Ethereum’s responsibility to make those guarantees clear and continue to strengthen the core protocol.