Cats are clean. Dogs are dirty. A dog is happiest when it's rolling in poo. Cats are smart, dogs are dumb. A dog will do whatever it's told to do. A cat will do what it wants to do. "Why should I do what you want me to do? You'll feed me either way." That's smart.
Cats don't smell like used litter. Cats wash themselves and smell clean. Your house can smell like used litter if you're too lazy to clean the litter box. That's your job, not the cat's. Your cat is not a dog. A dog works for you. You work for your cat. So which one is the smart one? Clean the litter box and your house won't smell.