Optimism Mainnet excels at providing immediate, low-cost access to a mature ecosystem because it is the canonical, high-liquidity hub of the Superchain. For example, it currently secures over $6B in TVL and processes transactions for major protocols like Uniswap, Synthetix, and Aave, with average transaction fees under $0.01. This shared security and deep liquidity make it the default choice for applications seeking maximum composability and user reach from day one.