Dark Knight was bad even in Endwalker but

[Ryaduera]

It's a player issue.
DRK got indirectly buffed as more magic damage got added in DT dungeons, the hardest hitting back even only use magic damage.
Healer alone are enough to prevent a tank from even dropping below 50%.

I will not be lying but I think it's tank or healer issues as a sch main I never ever struggled to heal a darknight often it's warrior that struggles because they only use bloodwhetting or the healing skill to be honest most darknight I have seen are even legit top tiers in play. I don't see why you think it suck (other then MP Regen)

I did the math on this and this is not true at all. Well, I guess saying DRK got indirectly buffed was true, but it wasn't enough and it's not every pull.

For PLD if you consider you can HS once every 21s roughly, we're going to call it once every 25s since, like I said, it's only "roughly" every 21s and we want consistency here. 120/25 is 4.8 casts of HS, which is split between 4 seconds of 27.75% damage reduction (Remember, since it's 2 buffs it has diminishing returns on itself) and 4 more seconds of 15%. That's 4x4 each, so 16 and 16. Bulwark lasts 10 seconds and while it isn't a flat damage reduction, it's essentially 20% reduction for 10s on a 90s cooldown, so you can use it twice in a 2 minute window. So to sum it up: ((16*27.75)+(16*15)+(20*20))/120=9.03% Reduction (Redacted for an edit, see below)

GNB is basically the same math but instead we change the 20% reduction on Bulwark for 10% reduction on Camouflage (Ignoring Parry rate as we ignore PLD Passive block): ((16*27.75)+(16*15)+(20*10))/120=7.336% Reduction

DRK we will start with full charges of Oblation, meaning we can get 3 off in a 2 minute window, but outside of that that's the only thing we have for personal and unique mits. Then we do the math again for magic damage, knowing full well magic damage is so rare and you almost never would use Dark Mind off cooldown to any effect. First, physical damage. Since it's just 3 Oblation charges at 30 seconds of 10% reduction, this is easy: (10*30)/120=2.5% reduction.

Include Dark Mind, you can get 2 off since it has a 60 second cooldown. Still easy math here: ((10*30)+(20*20))/120=5.833%

Honestly this surprised me. I thought DRK would pull through in magic damage reduction with Dark Mind in a 2 minute window, but it looks like being the "Magic Damage Tank" isn't even actually happening when the math is said and done. Keep in mind, the actual disparity should be even larger after considering PLD Block and the Camouflage parry rate, but I don't really want to add the math for those steps. As I said, though, it would only increase that gap. In longer durations, DRK should catch up in magic damage reduction eventually because Dark Mind cooldown is 30s less than Bulwark and Camouflage, but honestly 2 minutes is already far too long to be holding a pull. I think technically DRK pulls a bigger average in a 1 minute window for magic damage as well, but I'm unsure because longer durations will start to show the weakness of Oblations longer cooldown. In pulls you are taking mixed damage at best so you're probably somewhere between the 2 averages, anyway, so I'm not convinced that the Dark Mind cooldown can even help it catch up. In fact, I'm quite convinced it can't when you consider the far superior cooldown of the even better cooldowns the other tanks get at level 82.

For clarity's sake, this math is basically saying that if over the course of 2 minutes 1,000,000 damage is applied to the tanks (Just using an easy to quantify number) in equal amounts of damage over each second (8,333 damage per second) the PLD reduces it by 90,300, GNB reduces it by 73,360 damage, and DRK reduces it by 25,000, or 58,333 if it's magical. This is without standard tank mits like the standard 40%, 20%, 10%, and 20% slow from Arm's Length that is basically 20% reduction as well, as those are standards and this math is intended to show the difference between tanks unique cooldowns.

So yeah pretty sure Oblation just isn't enough and TBN isn't as efficient as it looks at a glance when you consider the total HP Shielded is about equal to the total HP a PLD can restore within the same 2 minute window. In a scenario with constant incoming damage, healing is harder to calculate actual efficiency since overhealing is health not used that shielding doesn't suffer from, but at this difference does that even matter? I also calculated the healing without crits because that complicates the math a lot. I think we have 15% crit rates now without melds and about 150% crit potency and I'm not about to do that part of the math.

These numbers show that DRK isn't even succeeding at the thing it was meant to succeed at. Oblation just isn't enough.

EDIT: Just did Expert as PLD and realized blocking is not 20% reduction, it's 16%, so to adjust the number, ((16×27.75)+(16×15)+(16×20))/120 =8.36% or reducing 83,666 from 1,000,000 damage over 2 minutes.

And here comes "But TBN increases defensives, too."

Yes... but not enough. This post shows that this has been untrue since EW (all numbers should still scale to be true, cannot test on current GNB yet, still not 100 on that one, but can extrapolate based on PLD healing potencies as well)

Ah, but you say the shielding works better in pulls than on tank buster? Well in GNB case that might be true, the total cure potency for GNB in a 2 minute window is 8100 potency, but it has superior damage reduction even vs magical, and then PLD can restore a total potency of 14,800ish which actually...

EDIT: Interestingly if a single 1000 potency heal on my gear is just over 30,000 HP then by that math PLD would heal around 300,000 hp with no crits or ramparts, which at 40k hp shielding from TBN is 7.5 total TNBs which also takes 2 minutes to burn through on a 15s cooldown if used entirely off cooldown. Obviously round up to 8. So if the healing without crits and without ramparts is actually the same as TBN, surely something is to be said for the extra damage reductions PLD gets from Bulwark, the greater value from HS compared to Oblation, and the passive blocking that does happen regularly? This kind of math is why TBN just doesn't work, it's too short term and with nothing to fill in the time inbetween when damage is properly taken. It's more damage taken with less health to bump survivability. The math is there, I don't know why the devs allow this to continue. Abyssal Drain also isn't really a heal to me, it's more of a "free bounce back once a minute" in pulls, but this could be attributed to my way of thinking with reliability and consistency and pressure to use it in burst windows regardless of current HP. That's why I haven't considered it into my numbers.

And in an environment where damage is continuous (Like dungeons) healing is just adding more HP to burn through just as TBN is. Even if you assume 10 targets on Abyssal Drain it still doesn't get anywhere near the other tanks healing abilities.

GNB is third in healing for tanks and in a 2 minute window the disparity is still almost ten times the difference. Even if we assume 200 potency per target on a pull from a pull of 10 mobs that's 2,000 potency every minute adding only 4,000 making it a 2 minute window of 5200 healing, less than half of GNB still. The math is there, DRK just can't compare to the other tanks.

So can we stop pretending that DRK being the inferior defensive tank is a skill issue? They even gave the DRK 99 weapon Tenacity but didn't give it to any other tank.

It's got nothing to do with the tank's job, it's a player skill issue. When leveling Sage I've had DRKs where I had to use almost no oGCDs because they use their mitigation, and WARs that require a lot of healing because they think they only need Bloodwhetting.

As a Sage, DRK is a good pairing because Kardia makes up for the lack of DRK sustain, but when I play warrior I let my HP get low low LOW because BW IS all I need. A single forced crit AoE and I am back at full health. Letting my HP drop is just efficiency to stop overhealing and some healers tend to just panic when they see it as if I can't just bounce back up anytime I want. Warrior doesn't need a healer from the level they get 56 on. If you're healing a warrior, it's because of your own anxiety that they might die; I assure you, they can't.