I’ve actually been trying to farm them lately and the drop rate is TERRIBLE. I’ve gotten a whopping THREE shiny drops in the last 2 days; collectively ~8hrs of farming.
-
It's actually a little known fact that the drop rates shrink and expand in a direct inverse correlation to how much you play. Play a lot, drop rates fall. Play very little...you get the best RNG. Look it up...many live service video games do this.