Sounds built from one long held vowel have circulated on soundboards for years because they need no explanation and work in almost any language. This one second version is the shortest form, shared mostly as a reaction clip rather than a clip from a named film or show, and it sits alongside other extended scream sounds in meme edits. Creators keep reusing it because the plain AAAAAAAA spelling in its original listing made it instantly searchable, and the abrupt ending leaves room for a cut, a freeze frame or a follow up joke.