He can also use his deflect to punish ranged characters, reflecting their bullets back at them and potentially eliminating them if they aren't careful. He's also great at tackling ranged characters like Widowmaker and Ashe, as he can use his mobility to reach them without ever entering their sight.
A good Genji can slip through the shadows and quickly eliminate a Mercy, Lucio, Kiriko, or Zenyatta, greatly hindering the healing capabilities of the opposing team.
This makes him an ideal character for taking down less mobile targets, as they will have an incredibly difficult time escaping the fleet foot ninja. There aren't many characters that offer the same mobility, as a skilled Genji is even capable of taking to the skies temporarily to slice through an unaware Pharah or Echo with his dash ability. Although Genji does have quite a bit of damage potential, he'll still struggle to take out a beefy Tank on his own. This means sneaking into the enemy's back line and laying waste to their exposed healers and damage dealers.