A group of 7 pre-made can charge people all day and guarantee a 1 shot, do it over 30+ times a day with out 1 person getting killed or hit by an AOE.
It's called your latency, your reaction speed, and your inability to realise that the animation dissapearing does not signal the definitive time it will do damage to you.

The fact that you can step out of the "circle" .5 seconds before it goes off, does not mean your safe. It means, that 1 second prior to that circle going away, is when the damage effect will mark who it will hit. The circle will then dissapear, and you will be hit.

The fact that people don't seem to understand this, are just slow.

You want SE to fix this? Yo SE, Shorten the duration of the circles on the ground (the animation) by 1 second. That will 100% fix the issue, because then people will be getting hit and see the circle lined up with the damage timer. The delayed damage seems to not be something these people understand is in the game.