How does value flow within Web3? It seems simple—token transfers, DeFi interactions, NFT trades. But behind the scenes, it all depends on a severely underestimated factor: whether data can be accessed and verified at any time.

This issue is called data availability, abbreviated as DA. It sounds very technical, but in reality, it’s like the "invisible killer" in the blockchain world. Many people only focus on transaction speed and costs, neglecting this aspect.

Imagine a scenario: a blockchain claims to process millions of transactions daily, with extremely low transaction fees. How is this achieved? Rollup technology compresses large amounts of transaction data and only submits a "commitment" to the Ethereum mainnet, with the actual data stored elsewhere. This approach indeed saves money, but here’s the problem—what if these raw data suddenly disappear, get hidden, or cannot be retrieved in time?

No one can independently verify whether the chain’s state is accurate. The entire security mechanism collapses.

That’s why DA has become a deeper "trust point" than transaction execution itself. It doesn’t directly handle value transfer, but it determines whether the records of these transfers are trustworthy and traceable. Without it, no matter how cheap the transaction fees are—because you simply won’t know what’s happening to your assets.

Now, some teams are re-examining this issue, attempting to rebuild data availability solutions from the ground up, making information flow more transparent and verification costs lower. Improvements in this approach could redefine the security costs and efficiency ceilings of Layer 2 solutions and even the entire Web3 ecosystem.