According to @VitalikButerin, "You can just build on L1," posted on X on Nov 30, 2025, emphasizing Ethereum’s base layer as a place to deploy applications, source: @VitalikButerin on X, Nov 30, 2025. On Ethereum mainnet, smart contracts execute directly on the base layer under Ethereum’s consensus security, source: Ethereum.org documentation on smart contracts and security. On-chain demand increases gas fees and burns ETH through EIP-1559’s base fee mechanism, directly linking mainnet activity to ETH supply dynamics, source: Ethereum.org EIP-1559 explainer and gas fees guide. Layer 2 rollups post transaction data to L1 and rely on Ethereum for settlement and security, clarifying how L1 usage and rollup activity are structurally connected, source: Ethereum.org Layer 2 documentation. For trading, the concrete on-chain metrics tied to potential L1 usage shifts are gas price, base fee burn rate, and the net ETH supply trend, source: Ethereum.org EIP-1559 explainer and gas fees guide.