I’d expect that this isn’t a typical story, do most dogs reproduce? I think if that were the case we’d quickly end up with too many dogs, their litters are so big.

Still seems like a pretty good deal for the species as a whole, though. Sort of like ants or bees, most of the members of the species end up as non-reproducing workers (except the work is to go be a friend to humans). Of course the ratio is not as extreme!