DAI is the only one of the big stablecoins that has complete transparency, and some amount of decentralization. You can see all the collateral backing the DAI. You don't need to trust that DAI is backed, you can verify that it's fully backed. With tokens like USDC and BUSD, you have to trust the monthly attestations coming from some 3rd party. Also, USDC and BUSD, being fully centralized, have the power to freeze addresses, making those tokens worthless. DAI is run by a DAO, and I believe the DAO does not have the power to freeze addresses. About 45% of DAI is backed by USDC, so if USDC goes down, DAI will be hurt as well, but not by as much.
