Cats are capable of a much wider range of vocalizations than other human pets, especially dogs; cats can make more than 100 sounds, while dogs tend to have only about 10 sounds in their vocabularies, meaning that cats are 10 times more loquacious than their other four-legged counterparts. However, this does not mean that cats are superior communicators in general; it just means that they 'talk' more and have larger sound vocabularies than dogs do. Dogs use other methods of communication, and are particularly adept at using physical communication to let people and other animals know what they need rather than simply relying on making sounds.
The fact that cats and dogs each have their own preferred methods of communication point not to a lack of complexity in one or the other but rather to the simple fact that these two types of domestic animals are quite different. Just as dogs do use vocalizations in addition to physical communication, cats also use physical cues in addition to their many vocalizations to let their desires and annoyances be known. Cats use a wider range of skills to communicate with other cats, including techniques that are mostly indiscernible to humans, such as chemical signals.