(almost) All L2s are essentially the same - so what matters is "CC" - Community and Connections (i.e. integrations you offer to builders and users alike).

Who has them ... here's your answer from Token Terminal 🤓

Base makes it easier for developers to build apps by offering seamless integration with Coinbase’s products, users, and tools. Access to 110 million verified users and over $100 billion in assets is kinda hard to beat advantage over building on other Layer-2s 😉
(apart from getting their airdrop money, ofc)

That's a great point! Connections to a large and established user base like Coinbase can be a major differentiator for L2s. The integrations and access to assets you mentioned are indeed a significant advantage!