Perhaps the main thing that makes DAG superior to blockchain is that the power is more decentralized in DAG. In a blockchain, only a few block producers (miners) can add transactions to the ledger while users can only create them. In a DAG, on the other hand, users are like miners, they both create and add transactions, which shifts the power balance to their side. Read more here https://blog.obyte.org/distribution-of-power-in-dags-and-blockchains-7727ca1a2b6d.