So, if a cat gives you it's loyalty and affection, it's because it wants to.
Well I disagree. If a cat gives you it's "loyalty and affection" it's only because it wants something in return (usually food) so a cat in IMO is somehow a "hypocritical" animal in the sense that it doesn't never have a real sense of loyalty and affection towards their human owner (due to like you said to their "loner nature").
Dogs are like you said a "pack animal" and therefore social animals that's why IMO their "loyalty and affection" is usually a true one. But don't be fooled regarding the dogs capability to survive alone, dogs (at least some races) are more than capable or surviving alone it's just that they prefer to live when possible in a "society" (the pack).
Anyway my favourite animal was a Parakeet that I had (sadly already died) which had drinks with me (whiskey, wine, etc...) with the exact same pleasure as a human being and replied (nodded) a YES when I offered something that it wanted and nodded a NO when I offered something that it didn't want, I would like to see a cat or even a dog doing that!