Lag is a real problem. Who here can say with a straight face they didn't get hit by plumes even though their character was outside the area? What it shows on screen and what actually happens is different.
The difference between experienced players and inexperienced ones is that they learned how to fight lag. You don't wait for stuff to appear on screen, you move slightly ahead. Not much ahead as to make others eat your plume but just enough and after many tries it becomes second nature to know the right moment. That doesn't mean lag disappeared now, it only means you now know how to deal with it for this particular fight. New fight appears, you have to learn again how to preemptively move and avoid stuff.
I continuously hear from new players "but I was out". Yeah, you were out of the area on your screen, in this game that doesn't matter.