"That's rough, buddy" comes from Avatar: The Last Airbender, spoken by Zuko during a conversation with Sokka. The line became a lasting reaction meme because its blunt, understated delivery fits so many online situations. Fans clipped it into edits, compilations, and short reaction posts, where it serves a similar role to bruh but with a more sympathetic tone. It is still widely used because the quote is instantly recognizable to many viewers and works well for both sincere and ironic responses.