FFXIV has some serious competition with WoW: Legion

[Duelle]

Actually, no, it doesn't. The problem is not with the existence of Hallowed Ground, but in the raid design to make HG mandatory. For example, in A1S, you have to use HG on one of the Plasma because you other skills would all be on CD. While DRK and WAR could keep Holmgang and LD safe for when things go really sour.

The fact Holmgang and Living Dead scrape the bottom of the barrel design and concept-wise supports my point of Hallowed Ground creating a problem, specially since the devs seem to agree with me on the fact that Hallowed Ground existing = every tank has to have a copy of it to be complete.

If you de-emphasize Hallowed Ground it becomes a get out of jail free card for PLD (moreso if you replace Living Dead with something else and remove Holmgang's invincibility), and that may mean a considerable advantage depending on the setting.

As a sidenote, in FFXI, PLD was the only tank to have an Invincible buff, yet it was frequently the less prefered tank.

You forget that the reason for that was NIN's ability to hold aggro and take no damage for prolonged amounts of time, far longer than Invincible's duration with a fraction of the cooldown timer.

I think the problem is that they want to create many many jobs. You can't really tank or heal with many different ways, so why not keep those roles with only a few jobs ? And give them different builds to steel cater to different type of players (No one complains that two builds of the same job have the same skills at the core...)

Considering builds are prone to one build ruling them all on top of this game's lacking variety (I want my DPS Red Mage that dresses like a french musketeer and sets their sword on fire), limiting the number of jobs is the last thing I want to see happen.

Tank and heal approaches are a combination of styles (AKA gameplay) and the mechanics behind the gameplay. I'll shoot off my usual list to illustrate my point. (NOTE: Not all of these are representations of how the jobs are currently designed, but I'm giving you possible concepts these jobs could be designed around to give them their own identity without being on different star systems performance-wise)

PLD: Straightforward tank with a shield and defensive cooldowns.
WAR: Builds wrath and spends it to mitigate or deal damage.
DRK: Drains HP from enemies with a focus on parries and reducing damage received.
BST: Relies on a high HP pool and high defense rating (because it combines the stats of the master and their pet) with a slight advantage in AoE damage (specially if said pet is big like a bear).
DNC: Mitigates damage taken by grazing hits and has a slight advantage in dodging attacks.

WHM: Direct heals, with healing cooldowns and some HoTs to supplement.
SCH: Focus on barriers and secondary healing via their fairy.
AST: Focus on HoTs and some direct heals.
CHM: Focus on heals that react to one another and heals that react to the target ally taking damage.
MYS: Some direct heals, some HoTs, delays damage received by target allies as well as converting some of the damage taken to HP for that ally.

Sure, you could boil all of these down to 2 or 3 jobs, but the thing is that not everyone wants tank as a dude in heavy armor. Likewise, not everyone wants to heal as a guy in a dress. We had someone on these forums not long ago asking for a more rugged style of healer because they weren't digging sparkly lights restoring HP. It may not seem important, but it's very damn important.