Dogs evolved (or rather more accurately, they were selectively bred) alongside humans to fulfil specific purposes like protection from attackers and predators, or aid with pulling things or help with hunting. Same for cats whose purpose was to keep your home and your granary free of rodents. Most pets don’t do those things anymore, with some notable exceptions like sheep dogs, rescue/service dogs, etc. Those are worthwhile purposes to keep them around for. But cats surely have become redundant, no?