I’ve ran into one obvious cheater in the past. They turned the stuff on midgame, it was visible in the replay that their pov erratically changed direction 180° a few times before they started landing 100% headshots on an invisible sombra and tracking heads behind walls.
And that was an arcade mode XD
I saw opponent with Play of the game review that turn 180 degree in less than 1 sec and head shot multiple within less than 1 secs so many times too. But report does not help much since those people will create another account and come back to cheat on the match again. I don’t mind fight against cheater or smuf but some of them cheat and sarcastic other because they know normal play can’t win over cheat. What make cheater proud of cheating in game I really can’t understand that 
I dont know, I played against cheaters that stucked in silver and bronze before. 0 game sense, and just stand in the open and hard lock aimbots. That was also back in ow1, so two shield tanks with a hitscan will delete that cheater lol.