Explosions

Mad of monsters using detonate dead and explosion, this game is Pearl Harbor Xd Everything explode all the time everywhere, even you kill rare at range there is always something you cannot see that kill you instantly, it's hell koz it's hard to find higher tier maps and you don't know why you die :(
Playing in group is a nightmare, too much spell effects, when will you add an option to remove other's players graphic effects ?!

Evidently, instant death both with and without apparent cause, with or without reasonable warning (...and thus without reasonable visual cue) is part of the intended gaming experience.

Traditionally, in games, part of the challenge is reaction to clear visual cues in order to avoid danger. In PoE 2, some dangers are visually subtle or effectively invisible, so exposure to them is an effectively random occurrence, especially with all of the other visual distractions (as you pointed out).