The sound comes from Minecraft, the sandbox game released by Mojang in 2011, where it was the default player hurt sound in early versions before being replaced by newer, softer hits. Players who started on those builds kept sharing clips of the old grunt, and it spread beyond the game into meme edits and soundboards as a shorthand for taking damage in real life. Its nostalgia for longtime players and instant readability for everyone else keep it in regular use.