Similarities:

• Both involves spending a lot of time and NRG to to increase a resource based on luck
• Both is an alternative to aquire a resource that would otherwise require dupes from pulling on gacha
• Both is the unintended way of farming the resource

Why it's worse:

• Frag dungeon cost 10x the NRG, and it's "competing" NRG pots with esper dungeon.
• The final payout for farming is "worse" (getting Dualcast/Dual-wield and such makes a fight a billion times easier, while STMR/EX levels nowadays only let you beat the dead corpse harder)
• You need to monitor how many shards you get to retry therefore no easy macro

Therefore, my conclusion is that I will not participate in this insanity. I learned my lesson.