Hide other players and their effects (PVE)
+1 but for WvW also!
https://forum-en.gw2archive.eu/forum/info/updates/Game-Update-Notes-August-6th-2013
Improved Effects Culling
In the open world, dungeons, PvP, and WvW, the new effects-culling system will slowly start reducing the detail of each effect in order to increase combat visibility when many effect types are overlapping.