Cat breeds have always been created purely for aesthetic purposes. Because of this, the main difference between breeds is their unique appearance: whether they have long fur or are hairless, whether their tails are normal or short, whether their heads are round or triangular, etc.
Behavior has never played a significant role in cat breeding, except that aggressive or overly timid cats have often been spayed or neutered. No one holds competitions at cat shows to determine the smartest cat or the most playful kitten. All prizes are awarded based solely on appearance. Beauty is the greatest weapon of pedigreed cats! :)