One of the great puzzles among scientists (they are called paleoanthropologists) who puzzle over things like this is why the Neanderthals became extinct while the ancestor of modern humans thrived and survived in the same habitat at the same time.
There are a number of theories, but a recent one that is gaining notice is that modern humans domesticated dogs and the Neanderthals didn’t.
The dogs helped the humans hunt more efficiently by locating quarry and boxing it in until the hunters could make the kill. Finding the game is often the most difficult part of hunting. Using dogs would have allowed the hunters to ensure a more plentiful food supply as they refined their skills and their weapons.
There is also evidence that dogs were used to carry the meat from the kill back to the place where the group was living. Even after feeding the dogs, the hunters would have been able to transport heavier loads and save more energy than they would have without the dogs.
Additional food generally has marked effects on the health of a group. Better-fed females can have more babies, can provide them with more milk and can have babies at shorter intervals. Before long, using pack dogs could have caused the human population to increase. American Scientist
Pre-historic dogs may have saved our whole species by domesticating us while we domesticated them.
As time went on dogs were used to guard the homesteads, shepherd the livestock, destroy vermin, and generally allow humans the freedom to build a civilization.