I know you didn't but I do think looks and size played more into the cultural habit than those qualities, which you can find in abundance in other animals such as cattle.
Cattle can and have been companion animals, they are trainable (in fact smarter at tool usage and problem solving than dogs), social animals with high empathy. Anyone who has hand raised cows knows that they will crawl into your lap if you let them. And follow you just about anywhere.
But most people don't have hands on experience with cows due to their not household size, and have been culturally trained to think of them as food, not companions.
Not ragging on dogs mind you. I love dogs. Just comparing and contrasting why the two are treated separately.