The Blockchain Trilemma and Performance Bottlenecks
Blockchain systems have long faced a classic challenge known as the “trilemma”: it is difficult to achieve decentralization, security, and scalability all at once.
In most Layer 1 public chains, ensuring security and decentralization requires a large number of nodes to participate in validation and consensus, which directly limits the network’s processing power. The more nodes there are and the stricter the validation, the slower the transaction confirmation speed and the lower the system throughput.
In other words, the performance bottleneck of blockchain is not simply a technical issue but a result of design choices. If high performance is pursued at all costs, decentralization may be sacrificed; if decentralization and security are maintained, some efficiency loss is inevitable. This structural contradiction is the fundamental reason behind subsequent scaling solutions.
The Roots of Gas Fees and Throughput Limitations
On blockchain networks, each transaction consumes limited computational and storage resources, so a gas mechanism is needed to price these resources. When network demand rises, users must pay higher gas fees to prioritize their transactions.
The essence of this phenomenon lies in the limited “block space” of blockchain. Taking Ethereum as an example, each block can only contain a certain number of transactions, while users worldwide compete for these resources at the same time. When demand far exceeds supply, fees naturally increase.
This issue can be understood from several perspectives:
- Block size and block time limit the number of transactions processed per unit of time
- All nodes must repeatedly execute transactions, increasing overall computational costs
- Popular applications (such as NFT and DeFi) can occupy resources intensively in a short period
Therefore, high gas fees are not an occasional problem but a direct result of on-chain resource scarcity and growing demand.
The Evolution from Layer 1 Scaling to Layer 2
Facing performance bottlenecks, the blockchain industry initially tried to solve the problem by enhancing Layer 1 capabilities, such as increasing block size, speeding up block production, or adopting higher-performance consensus mechanisms. However, these approaches often impact decentralization or security, so there are clear limitations.
With technological progress, the industry gradually shifted to another approach: migrating part of computation and transaction processing off-chain or to second-layer networks, while submitting final results back to the main chain. This is the core logic behind Layer 2.
The basic concept of Layer 2 can be summarized as:
- Handling high-frequency transactions off-chain to reduce the main chain’s burden
- Using the main chain as a security and settlement layer to ensure final consistency
- Improving overall efficiency through batch submission or data compression
This architecture retains Layer 1 security while significantly increasing system throughput and user experience. With the development of technologies such as rollups and state channels, Layer 2 has gradually become the mainstream path for blockchain scaling.
