Yo-yo Ma plays a wide range of genres, from Bach to Chinese folk. He does not specifically focus on one type of genre, classical music. His transient style capitalizes on popular genres and artists to reach relevance. He is not necessarily providing a novel musical experience to the public.
There are many great cellists in the world, and the criteria for a cellist's skill is purely subjective. Although Yo-yo Ma had a large influence on popularizing music to the world, other cellists, such as Pablo Casals, might be the greatest cellist of all time. Pablo Casals made the most popular Bach recording ever and made a bridge between the modern age and classical music.