He was a poor leader who did not want to handle economic issues (France's debt)
He was given the throne in serious circumstances. France had helped many U.S. colonies to gain independence from the common enemy Britain. This was a big load on the state's treasure. Most of this was taken by loan which doubled with interest over the years. Poor Louis 16 couldn't handle it. He was forced to increase the taxes. People were already starving. This lead to the revolution.