Not long ago (I believe it was around the time of the soulburn nerf) several classes got a significant reduction in latency in some of their core rotation skills, regardless of the ping of the player.
Most notable among these were BM(Flicker), WL(Bombardment), Des(Wrath/Eradicate), and Sin(Heart Stab).
At the time there was no official mention of this in any patch notes, and it has remained this way, meaning it could only have been an intentional update.
It's made a lot of more latency heavy classes feel very left out, particularly SF(Right Punch/Cobalt Punch/Dragonfury), FM(Bla