they need to make dungeons with optional branches. every dungeon, every time you have to complete every objective.

all the 4 man dungeons right now are kill 3 bosses, get 1 chest from each, get myth at the end.

how about
- go East, kill a mini-boss that gives an extra 25 myth.
- go West, get locked in a room that throws 20 mobs at you, survive and get a chest with an item that you don't get from killing the main boss.

both are optional, don't want either of those, skip them and just clear the main boss.

or have meaningful time limits, with different bosses/objectives that will give you time extensions. if you're overgeared and super-skilled, just skip the time extension bosses and clear in 15 minutes.