In general, i think that the main issue for NOT doing certains path/dungeons are the incredible lenght of certain encounters…
Dungeons are not so difficult after all, but some fights get terribly boring…and not for mechanics, but only for a matter of health pools! The destroyer boss in CoE (even if it’s since the new patch that i don’t get in there, maybe something has changed), subject Alpha (VERY funny combat dynamic but way too long for a boss you meet 3 times/run), +1 to the insane health pool of final bosses in HotW….
That should go this way imho: more mechanics with faster fights