Has an AFL game ever ended 122-79?
Exactly once. On August 10, 2018, Essendon beat St Kilda 122-79, and no AFL game before or since has ended that way. When it happened it was a scorigami, the first 122-79 in league history.
That makes 122-79 the 3836th most common final score out of 6,607 that have ever occurred in AFL. One point away, 123-79 has happened 3 times and 122-80 has happened 4 times.