Over time, the differential rate of reproductive success emphasized traits that were not only useful but pleasing to human emotions and actions, in particular those related to our social interaction, bonding, and nurturing instincts. Dogs may not even be "domesticated" in the strictest sense of the word, but rather a symbiotic species that co-evolved with humans.
It occurs to me that domestic animals are (certainly in a moderately-warmish climate) all that's required for a "fine", "humane", "quiet pleasant" human civilization. Not a highly industrialized one perhaps, or a highly complex hierarchy of state and formal roles, but still, if & as long as humans could use enough of their gray matter to reign in their own breeding in sync with pasture-land availability and domestic-animal breeding.. seems even for metal-working and old-school defence (perhaps useless in the nuclear age) is quite doable without industry or slavery indeed. Something the doomsday preppers would be wise to keep in mind and focus on, rather than memorizing what small proportion of calorically meagre, highly seasonal, local herbs/mushrooms/nuts/berries aren't immediately deadly / long-term damaging, or wasting valuable pasture space trying to sprout a some silly freedom fries ;) one cow feeds a man for 12 months, or absent freezers, 12 men for a month, with full nutrition and copious kcals, nothing else will ever beat that. Smaller animals are a decent hedge and for variety.
Perhaps this comes under 'defenders of the realm', but: dogs bark at strangers thereby acting as an alarm system.
I wonder if dogs domesticated themselves, at least to begin with. By following a human camp around they would be more likely to breed with other human-liking and human-tolerated dogs.