Has an AFL game ever ended 84-55?
Exactly once. On July 30, 2022, Adelaide beat Carlton 84-55, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 84-55 in league history.
That makes 84-55 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 85-55 has happened 4 times and 84-56 has happened 4 times.