Myles Garrett fought Mason Rudolph because he felt disrespected and insulted by his behavior on the field. Mason Rudolph had called him a racial slur and tried to pull off his helmet during the game, which is a serious violation of NFL rules and an act of disrespect towards an opponent. Myles Garrett felt that he needed to stand up for himself and defend his honor as a player. He felt like he had no choice but to retaliate, and so he grabbed Mason Rudolph's helmet and swung it at him.