Some DRK changes seem annoyingly simple yet are ignored....

[Shurrikhan]

But TBN being tied to and almost the entire reason for MP management is WHY the job has become so tuned down and honestly bland.

TBN has nothing to do with the degradation of MP management.

What you're doing is like blaming Shinten/Kyuten for the loss of unique costs on Guren/Senei and the pruning of Kaiten and Seigan and if Yaten/Gyoten lost their Kenki costs and damage. They're not the cause; they're the sole survivors.

Likewise, Dark Arts, MP costs on other skills, etc., all existed simultaneously with TBN. The same period in which we got TBN also gave us the most involve MP manipulations and thematic means of sustain that we've ever had, and to which TBN was synergetic, not mutually exclusive.

TBN didn't remove Darkside, Dark Arts, Dark Passenger, or spammable Abyssal Drain. It's simply the sole survivor of intentional simplifications.

costing MP isn't "flare,"

Costing MP is, however, the reason TBN can be as flexible as it is, allowing 50% barrier HP (2 casts at 25% each) compressed into as little as 9 seconds. Meanwhile, embedding Oblation into it would both waste its scaling value on non-tanks targets and make TBN itself less flexible.

Not that the other tank's low CD defensives are "skill intensive," but they all have auxiliary effects that aren't just "use damage ability you'd have used anyways" and actually provide for and emphasize a playstyle that again isn't just "costs MP."

The upgrades literally reduce skill ceiling compared to the original version of those skills. The HoTs make a large portion of their on skill's sustain less responsive, less important to time correctly / more worth simply hitting on CD, and Excog is literally autonomous. The inflated upper first half with extended window, meanwhile, reduces the reward of preemptive activations.

And TBN's reward isn't "use damage ability you'd have used anyways". That's neutral. Its auxiliary reward is MP-banking, since you can spend 3k MP before raid buffs to then have an extra 3k MP's to spend during raid buffs. Which is itself trumped by the flexibility of the actual defensive.

And sure, maybe the DRK felt the best right when TBN was released, that's subjective so I won't deny anyone that sentiment and there's plenty of reason to feel that way, but that was YEARS ago, we've moved past that period of time and the DRK is being left behind because of this apparent need to maintain this now subpar defensive ability.

Not remotely my point. You are claiming that TBN is incompatible with more involved MP management, but anyone who played before Shadowbringers knows it wasn't. Anyone who played earlier has literally played with far more involved MP management even outside of TBN and would remember that TBN was synergetic with those other, and far more numerous, sources of depth, not mutually exclusive with them.