Yes, wet (canned) food is better for cats than dry and contains more of what they need. Dry food is full of carbohydrates - something cats don't need and many have difficulty digesting. Dry food also uses up lots of water while being processed by the cat's body, and is suspected of contributing to kidney disease and FLUTD (urinary blockages).
Canned food is much closer to what a cat would eat if left to fend for himself outdoors (ex. chipmunks, mice, a bird now and then). Basically, fresh meat. You won't find cats out hunting for cereal which is pretty much what dry food is.
Make sure you feed a high quality wet food - no by-products, corn, wheat, no artificial colors, flavors or preservatives.
IMO, dry food (the best you can find, avoiding the same poor ingredients listed above for wet food) is fine for treats only, not as a meal. My little guys love running down the hall chasing after individual dry food pieces!