WETH is primarily used as a medium of exchange on DEXs and other DeFi applications. It allows users to trade Ether for other ERC20 tokens on DEXs like Uniswap, Curve, and Balancer without the need for an intermediary.
Additionally, WETH can be used as collateral in DeFi lending platforms like Aave and Compound to borrow other tokens or earn interest on the WETH itself. Overall, WETH plays a critical role in the Ethereum DeFi ecosystem by providing liquidity and enabling the seamless exchange of assets.