I'm a research mathematician working in Tao's field. I'm not claiming to be as prolific as he is, not by a long shot -- but other mathematicians do understand, critique, develop, and engage with his work. Indeed, many of his papers are collaborative with a variety of other mathematicians.

Picture him as the star player on a basketball team. He may be the strongest player on the court, but he's still playing the same game as everyone around him.