It must not see DAI as a competitor to Coinbase's stablecoin USDC.
Dai is a decentralized stablecoin running on Ethereum that attempts to maintain a value of US$1.00. Unlike centralized stablecoins, Dai isn’t backed by US dollars in a bank account. Instead, it’s backed by collateral on the Maker platform. If the Dai credit system is upgraded or shutdown, Dai holders will receive an equivalent amount of Ethereum (ETH) in compensation. Learn more at makerdao.com/whitepaper.