I'd argue some of the shit you can do with TBN and resource pooling is harder than anything you'd see on WAR by a mile and it is as a whole a lot less forgiving than WAR. But thats not me saying DRK is hard or has much depth, its me saying theres two tanks that are really, really easy and have no depth outside of pool resource, hit resource spender.
Infact I really want people to realize thats how we got here with tank balance, Square Enix didn't sit down and decide "this is going to be the big damage tank".
There was no design decision at all.
DRK is the only tank that has no defensives that upgrade as you level it, while other jobs will get expanded tools on their core kit, DRK gets a random oGCD that doesn't play into any of its resources.
Hell, until 6.1 where they finally put Stalwart Soul at a reasonable level, a good chunk of DRK's kit wasn't even usable in dungeon content in the lv 60-71 range. It just existed in this broken state and SE didn't care enough to touch it until 6.1
Funny enough its still kinda messed up as the new lv 40 Stalwart Soul says it gives you Blood Gauge, that thing you don't even unlock until lv 62.
And thats just how the job has been designed ever since its joke of a rework way back when. And now with EW I view it as a straw that broke the camel's back situation.
How many unrelated damage only oGCDs can you shove into a tank until their burst window beats out most DPS classes?
I guess the answer is 12 and a summon that casts 6 more at a higher potency.
Similar story with its defenses right now, DRK has strong raw mitigation not because its a design intent, but because while other jobs got moves like Raw Intuition, or Sheltron, DRK got things like Dark Mind.
Which isn't a bad skill, its just one of many skills that never really lead anywhere, Short CD magic only mit thats neat. Come EW, we saw other jobs Defensives upgrade into new skills, DRKs didnt, it got Oblation.
Which again, isn't a bad skill, short cd 10% mit on a double cast, but its leading to this point where other Jobs will be using their evolved mitigation skills to some effect.
And DRK will just kitchen sink it with every single skill its ever been given and end up with a higher number. Kinda perfect storm that Oblation and Dark Mind have the exact same upsides of being low CD.