What makes DAGs incredibly fast is the ability to parallelize: since blocks made in parallel are all considered valid (unlike in blockchains where all but one of them will be eventually orphaned), increasing parallel block rates does not harm security, thus removing a major obstacle to throughput (but one should be extremely careful not to enable new forms of attack, which is essentially what makes DAG consensus protocols so difficult to design).
One of the supposed benefits of the increased block-rates is the increased transaction throughput (another benefit, which I argue is actually the more significant one, is the greatly decreased confirmation times). On the surface it seems that if we make 600 blocks for every Bitcoin block then our transaction throughput is 600 times that of Bitcoins, but is it the case? Well, not quite…to find out more read Shai Deshe’s full article in it’s entirety here: https://medium.com/@shai.wyborski/transaction-collisions-and-the-effective-tps-of-inclusive-blockdags-20bdd6c60695