The Daleks are a mysterious race of aliens bent on exterminating every non-Dalek being in the universe. As such, they are not akin to blasting apart every atom in the multiverse to achieve this goal.
Once, they tried to destroy the multiverse with a reality bomb. This plan failed thanks to Blackout, Kakamu, Zev Raregroove, Malygos, BoM_Master, Artrix and TMV.
Then they returned and tried to attack Atlantis.
During the Uterio War, the Daleks sided with Uterio di Armechio. One of their kind served as a prison guard, and many more defended Mordor when the Rebels invaded it.