It feels like all of the discussion about the stances revolves entirely around numbers, which says a lot about how much of a band-aid fix they are.
What about the gameplay, though?
Ultimately, the stances have next to no impact on your rotation.

For PLD, it literally doesn't matter what Oath you're in, because they have zero interactions with your other abilities.
And what do they actually do?
- affect how much damage you take
- affect how much damage you deal overall
- affect how much damage your auto attacks deal in particular
- affect how much enmity you generate
- affect how your thoroughly underwhelming gauge is generated
Of these 5 effects, 4 merely concern esoteric numbers that don't impact your gameplay. The only potential interaction there is the generation of your Oathgauge, which in itself is rendered moot because - as I said - Oathgauge is garbage. If you gave Sheltron and Intervention 2 charges and a shared 30s CD, you could slash Oathgauge from the game altogether with nary an impact on the job.

How is DRK looking in comparison?
Having Grit on or off determines which of 2 resource-generating CDs you have access to, and how much MP is restored by Syphon Strike
Admittedly, this means that Grit does a lot more than PLD Oaths, but it's still pretty darn limited.
The choice between Blood Price and Blood Weapon is mediocre IMO, because both once again only affect arbitrary numbers. Syphon Strike's MP generation is a bit more impactful, but even that is less than it should be, because you're spending most of your MP on Dark Arts, which is a oGCD spell that only boosts ...numbers.
It's like everything about the design of tanks is married to potency and other arbitrary numbers, rather than the quality of your gameplay.

As for WAR?
WAR is the job I have the least experience with, so I can't really comment on it much. Giving you the choice between the self heal via Inner Beast vs the extra damage from Fel Cleave is a step in the right direction, but it's smothered once again by the lackluster damage output of bosses and the meta's obsession with DPS. And if you move over to your other pair of spenders - Steel Cyclone and Decimate - you're back to clinical numbers differences again.

So what to do with these stupid things?
I say cut the lot altogether.
WAR would need some attention, but PLD and DRK would barely even notice. Stances are a husk of a mechanic that has next to no gameplay value. They do nothing - including the arbitrary numbers they do affect - that couldn't be accomplished in other, more streamlined and less community-splitting ways