Its a dirty job, but if they donlt do it, grazed land productivity goes down for plants and grazing mammals.

"DUNG BEETLES. Certain beetles of the Scarabaeidae family greatly enhance nutrient cycling by burying animal dung in the upper soil horizons. Many of these dung beetles cut round balls from large mammal feces, enabling them to roll the dung balls to a new location (Figure 11.8). The female dung beetle then lays her eggs in the ball of dung and buries it in the soil. Dispersal and burial of the dung not only provides a food source for the beetle larvae, it also protects the nutrients in the manure from easy loss by runoff or volatilization—fates to which the nutrients would most likely succumb if left on the soil surface. Dung beetles therefore play im-portant roles in nutrient cycling and conservation in many grazed ecosystems.
Several thousand different dung beetle species are known worldwide, many having evolved to specialize in the burial of dung from particular mammal species (elephant, cattle, buf-falo, etc.). Rapid burial of dung by beetles also prevents the reproduction of carnivorous flies and other pests of large dung-producing mammals. Where native dung-burying “engineer” species are lacking in a grazed ecosystem (such as a savanna, a prairie, or a pasture), scientists have found that the introduction of appropriate species of dung beetles or earthworms can greatly increase the amount of vegetation produced and the number of grazing animals supported."
Quoted from Weil, R and Brady N. 2016. ORGANISMS AND ECOLOGY OF THE SOIL. Chapter 11 in The Nature and Properties of Soils. 15th ed. Pearson Publishing.