Not at all. He is prone to showing off a bit more than is necessary, but he is the most powerful human in our world. He can use all four elements, and with the Avatar state he has access to the experience and power of literally hundreds upon hundreds of individuals who have all mastered the elements and learned different techniques. In the past avatars have separated land masses, caused massive volcanic eruptions, hurricanes, tidal waves, you name it. He may have a rather silly disposition at times, but he has great power and strength within him.