After 1 (arguably 2) expansions what is square trying to achieve with WAR (and PLD)?

[Absurdity]

I think the idea with WAR is that it's supposed to be a bit more squishy than the other tanks, but compensate with self healing... Rather than having as much defensive options as other tanks, they'd have more ways to heal themselves. But aside from dealing with magic damage, they basically have as much defense as DRK or GNB does.

Once upon a time they did actually have weaker mitigation. But as Lyth said, mitigation is just binary most of the time, either you survive or you don't, and we can't require our poor little tanks to actually have to think outside the box and coordinate with other players to make up for their weaker defenses.

Funnily enough in the few cases where it isn't binary WAR does actually still have weaker mitigation, Abyssos' bleed busters showed how mediocre both Thrill and Bloodwhetting can be when it's not just a singular pass/fail check.
It always had and still does have weaker % mitigation, but there are so few fights that actually punish it for it that this flaw might as well not exist.

You know what else Warrior gobbled up from Dark knight? Reprisal and low blow.

Let's not conveniently pretend like Warrior was the only tank that got those two.

And in EW, Warrior also needed Dark knight's damage apparently. And now there's literally nothing left to take, Warrior is just flat out better.

Not like it could've stolen DrK's damage in ShB, they were both at the bottom lol.

[rawker]

Let's not conveniently pretend like Warrior was the only tank that got those two.

Cries in Convalescence.

[Absurdity]

Which is an inherently flawed idea, making a role something it's not in an attempt to attract people that don't want to actually play it.
Sure, it will get player numbers up in the short term because now all the DPS players will at least try it out, but they're DPS players for a reason and will eventually just return to their chosen role.

And now you're stuck with jobs that appeal to neither the DPS players you tried to cater to, nor the original players of said jobs.

[Nicola_Kunu]

Which is an inherently flawed idea, making a role something it's not in an attempt to attract people that don't want to actually play it.
Sure, it will get player numbers up in the short term because now all the DPS players will at least try it out, but they're DPS players for a reason and will eventually just return to their chosen role.

And now you're stuck with jobs that appeal to neither the DPS players you tried to cater to, nor the original players of said jobs.

This here is genuinely my biggest worry when something becomes changed, or simplified to be more accessible to others. The chosen path doesn't always feel like it's building on what exists to improve it and retain the same feeling or job identity.
For example, Paladin gaining Holy Might is a positive improvement that retains the core job identity and adds flexibility, Paladin having Goring Blade turned into a 700potency Boring Blade nuke is a negative change as made the ability feel worse and just feels slapped into the rotation.

These types of changes can be attributed not just to tank roles, but Samurai's Kaiten removal, Summoner's lobotimisation, Healer 1-button gameplay, etc.

I understand that the game needs to change to be fresh and exciting or else we might feel the gameplay stagnates, but if the changes upset the core or developed audience of a job, then it runs the risk of not being played anymore - especially if the new audience doesn't latch on.
That being said, Summoner has had their new audience definitely latch on as its one of the most played classes (likely because it's incredibly easy to play, and maybe it sadly fell on the chopping block because they needed an easier class?)

Healers have been lobotimised for a long while into 1 button gameplay and it prevents my desire to try any them out as well. I picked up Astro a long while back because I thought the random card effects sounded cool, but that's been stripped, and as such I have very little desire to play it. It's been made more accessible, but at the cost of interest from players. Scholar gameplay used to have DoT/Poison gameplay, but it no longer exists, so I don't think I will ever bother trying it as the core gameplay is fundamentally a clone of the other 3 healers and there's nothing to uniquely appeal to me.

As a Microsoft Producer speaking about AoE Online, Kevin Perry, once said, "You do, I think in general, annoy your core at your own peril."