The keyboards and mouse vs. controller debate is a pretty hot topic in the Warzone community. Many streamers and top pros have been asked for their opinions, which has only fueled the fire. A well-known pro for over a decade, OpTic Scump, recently gave his opinion on it.
Scump seems to believe that when it comes to competition, it really doesn't matter. He has played against people on both sides without ever blaming the input they used; in fact, many professionals do not do so. He believes this is an insanely irrelevant discussion.
Warzone Keyboard and mouse vs controller
OpTic Scump is one of the best Warzone players in the world, and he has proven it numerous times. In response to Myth's recent claims that pro players who use controllers aren't top FPS players, he had to respond. Despite respecting Myth, he cannot understand why this topic has been so hotly debated when it makes no difference to him.
Video from my friends at Esports Talk (start at 00:59).
As a general rule, the input does not matter at the top level. Warzone pros like these can beat normal players regardless of whether they use a keyboard and mouse or a controller.
To quote Scump:
"I mean, my f***ing perspective on it is who gives a f*** what you use man? Like, who gives a f****... You play on PC, you play on PC, good s*** man. You play on controller, you play on controller--Who the f*** cares. Like play what you like, use what you like, and stop b***ing."
There are instances when the controller is better, and there are instances when the keyboard is better. In the end, your K/D will reflect your skill, not your input. Pros can do well on either keyboard and mouse or controller, so streamers need to stop blaming anything but themselves (and hackers).