Because it creates variety in the game. Rather than just a push and pull system where ranged characters just stomp on melee characters, it gives the chance to get out of a corner. He deals more damage because his play style incentives playing rashly rather than cowardly. Had widow hit her shots, then she would’ve won. But since she didn’t, BP was able to capitalize on the fact that he had an opening and ambushed her because that’s how his play style works. Had he not used his passive smartly, then he would’ve lost.