Dogs are more loyal and friendly. They can also be trained to be a police dog, a guard dog, a hunting dog and more. If you get a cat, They will bring back dead cockroaches and rats to your house and you will have to clear it. Most cats are not friendly. There is no such thing as a police cat. Dogs can smell better.
Dogs are sloppy dirty and cannot be potty trained. Would you want a mutt to wake you up at 3 AM to go poo. They bark a lot and make too much noise. Yes they can be trained but so can cats. Cats are clean, neat and can be potty trained. They don't bark and they're loving and affectionate. I can state a billion more reasons why cats are better than dogs
"Dogs are more loyal and friendly." That just means they're more submissive, and are unable to show a great deal of independent thinking. Try telling a cat what to do, however, and you'll find that they have their own plans. Sure, they'll be your friend, which is good for them, but they won't be your loyal follower if that's what it takes to get a feed. They'd rather find their own food. Dogs, without a figure of power in their "group" will have trouble doing anything at all constructive n their own. Cats, on the other hand are natural, solitary survivors.
After all, would you rather have a brainless sidekick or a honest friend that'll let you know if you're doing the wrong thing by him/her with a smartly executed claw to the face?