I have had this same issue now for quite some time. I have a 9900k with a 2070 and 32g of ram. I have tried no add-ons, set all setting to low, and every other tip given. I have also used the resource monitor to show that all cores are even at about 75% utilization with very little spikes. out in the open would I get about 120-130 fps, in major hubs I get about 60-75 fps. In raid I get at best 24fps and as low as 13fps when the fight starts, out of the fights I am back to just over 100 fps. the only setting I leave at the highest are the ones to show what to avoid, spell effects are set to only necessary, but it looks like I am still able to see all the other peoples effects anyways. I am wondering if this has something o do with it