Why? Mostly for fun special occasion photo-ops with your pets. Maybe to get dressed up for Halloween or enter a dog parade or cat parade if those even exist.
Cat parades. Ahahahaha! Yeah right. The parade in which all the cats put on cat wigs and cat neckties and then run under the couch and hide.
So let's maybe nix the whole "Cat Parade" idea and stick to maybe really cute cat family photos and stuff.