No, nyet, non, nein, la (that's Arabic) -- cats do not need kibble. Kibble is easy for you to feed because it's cheaper than canned food, keeps well and can be left out without spoiling, but it doesn't give your cat what he needs to meet his basic nutrition requirements.
Kibble contains far too much starch for a cat, and not enough protein. Cats are pure meat-eaters and can't digest vegetables well, so even if protein is present in vegetable form, it's not the right kind of protein for them. Canned (wet) cat food or raw meat provides more animal protein that a cat can actually use.
Cats can digest carbs, but carbs are high in calories. "Good" kibble contains something like 35 to 50 percent of its calories as carbs, and "bargain" brands even more. A cat in the wild would get only 2 to 3 percent of his calories from carbs. Carbs also wreak havoc on a cat's insulin production and contribute heavily to obesity. A fat cat is not a healthy cat.
Cats are basically desert animals and tend to drink water sparingly, getting most of their fluid needs from their food. Kibble contains less than 10 percent water, while canned cat food and a mouse are about 75 percent water. A cat on a regular diet of kibble is likely borderline dehydrated and subject to urinary tract problems.
On a diet of mice and other small animals, cats eat and gnaw the raw bones, and this cleans their teeth and provides calcium. Cats on kibble or canned cat food don't get these benefits. Kibble is usually swallowed whole because cats don't have grinding teeth, and even if they chew it slightly, it gets moistened by saliva and tends to stick to and get caught between the teeth. This compounds the problem of plaque and tartar instead of solving it. To give your cat a treat that's healthy and helpful in many ways, toss a raw (never cooked) chicken neck into the bathtub and watch him stalk it, kill it and eat it, using every muscle in his body in the process.