Why do so many streamers say “Double u (f) in the chat”?

So, there are definitely more facial expressions and gestures than emojis on the internet. For example, there's a skeptical-confused-happy look and a skeptical-angry look; there are gestures like scratching the back of the head, and much more. There aren't emojis for many things. I wonder why. Because, for the most part, bored people on the…