Vitalik Buterin said in a reply to netizens on X: "The key thing that we are really in the early stage of is that L2 will eventually be affordable. Since 2020 (if not earlier), I have been saying that the entire 'not just high-value DeFi' part of the crypto field can only work if transaction fees are cheap. It was not until March of this year that they really became a reality.
If I were to choose the second and third early areas, they would be:
2. ZK-SNARKs and use cases (zupass, railway, 0xbow, rarimo, etc.) are finally close to maturity.
3. Account abstraction
ZK-email (and zk-wrapper similar to centralized ID) is particularly important, connecting the two."