The tank deliberately lets him get hit by multiple AOEs in thrash pooling...

[Hubert_H]

.. - why it is not good?

I've met this post in the closed thread, so I cannot answer it directly.
However I feel that the approach 'I'm a tank so I'm standing still inside trash mobs AOE, now go gather all your tools and heal me!' is kinda live and popular.
There are variations in the thread like 'I move out of AOE only if they apply debuff'.

https://forum.square-enix.com/ffxiv/...=1#post5833028

So I've registered just to answer on that post.

My general mental-checklist when tanking trash pulls is:
1. Can I move out of the orange without significantly shifting the mobs? Yes? Then shift the minimum needed (and ideally shift back afterwards).
2. Are the mobs probably going to die in the next 5-7 seconds, and I can survive this damage? Yes? Then just mitigate as best I can and eat the damage; the mobs will be finished off shortly and there's enough time to heal on the way to the next pull, and moving enough that the mobs might move out of DPS AoEs is counter-productive.
3. Does the healer seem to be really struggling for whatever reason? (Poor resource management, having had to spend all healing resources on a DPS standing in bad and eating damage like they're at a county fair pie-eating contest, lack of understanding of their healing kit, etc.) Yes? Then make it easier on them and shift out of the orange, even if it means shifting the mobs around.
4. Conversely, is the healer really good with their kit and has me as a tank feeling functionally immortal? Yes? Pop a second cooldown if applicable and hold my ground while laughing maniacally to myself. (That last bit may only apply when playing WAR or DRK.)
5. If none of the others are true, can I move a tiny bit so I only eat one orange blob instead of three overlapping ones or whatever? Yes? Then shift to take the minimum number of hits.
6. Failing all else, just move entirely out of the bad.

It's generally not so much a conscious choice to run down the checklist, that's just sort of a summary of what I know goes into the gut feeling of "should I stay or should I go now" when there's a marker proclaiming that the Bad Stuff goes right here under me in a trash pull. So far, this has generally served me well.

(Boss fights are obviously different, because generally in boss fights you're meant to move out of all the Bad Stuff.)

The quote above is about a light party (cause 'the healer'). Lets ignore low level dungeons and say that every player have its AOE skill.

(divided into multiple posts due to restrictions)

[Hubert_H]

There are tanks that use that 'significantly shifting the mobs' approach too conservative and end up not moving at all. Once I had the tank in Bardam's Mettle that just was standing still while trash mobs were pouring their AOE on him and me finished just spamming Eukrasian Diagnosis cause other skills were all spent.

What happens if 'the healer really good with their kit and has me as a tank feeling functionally immortal'?
The healer is seeing tank's health melting as a snowman in the summer sun. If that isn't going to stop stop he [the healer] ends up dumping all his emergency oGCDs. Then he just locks all his actions on repeatedly healing/applying shields on the tank. Then the healing of entire party is cannibalized to the priority task of keeping of tank and healer alive.

1. Considering most healer oGCD cooldowns are between 60-120 sec, this approach could leave the healer more or less empty-handed on the start of the boss fight.

There is a chance that is somebody will fail mechanics, things will go nuts, and the healer having less resources than it could if the tank just didn't blindly eat all trash AOEs.

2. Every player in a light party is a DPS. There are 2 dedicated DPS and 2 sub-DPS: namely tank and healer. Locking the healer exclusively on healing the tank task would exclude healer DPS from the party.
Healer is not a tank babysitter, he just have some other tasks to do as well.

3. Have you ever had 'I'm a DPS and healer seems to ignore me' experience? Sometimes it was just a derivative of 'Myself is a tank, myself is strong, myself catch every hit' tank approach. DPS healing will be sacrificed cause the tank loss will cause the party wipe, with pretty high probability.

4. I see no sense in 'without significantly shifting the mobs'. Your DPS will use AOE skills for any group of 3+ mobs, and that is 95% of trash pulls. Only melee DPS have some positional skills, and for single target only. So positionals IMO matter for the boss or adds only.
Most dungeons have simple design, there is a room/end of corridor before the gate/wall section. Fill free to maneuver there. Just do not make mobs face your party and don't split melee and ranged mobs, better to keep them together.

[Amenara]

In trash pulls in dungeons there is no reason to not move out of AoEs. Like you said nothing has positionals so you aren't affected by that so there is no real need to ever eat AoEs on trash.

For bosses it 100% depends. Zodiark EX I will intentionally eat every AoE that pushes me out of melee range since nothing in that fight hurts enough for me to care and I can just heal myself back up to full anyway. For fights that give damage downs for debuffs instead of vuln stacks I will avoid every AoE to keep from getting that debuff.

[Picker]

Shouldn’t tanks be constantly shuffling the pack around anyway? Like if the tank is standing in the middle of a pack then there’s no way aoe is hitting all of them

[Espon]

When tanking, it's easy to avoid AoEs without really shifting the enemies around as long as you move through them. Melee don't need to worry about positionals at that time as they should be using their AoE skills, so it does not matter if the enemies suddenly face another direction. Regular enemies typically don't have cleaves either so you don't have to worry about them facing the party. This also makes it easy to keep enemies in persistent AoEs, such as Doton and Slipstream.

During a boss fight, sidestepping is usually enough to avoid an AoE while keeping the boss facing away from the group. If you got to back out, then use your gap closer once the area is clear. Bosses tend to pause after using an ability, allowing you to step back into position without causing the boss to turn or step forward.

[DanielNegreanu_Adamantoise]

If it’s a full blown w2w you should do your best to mitigate damage and if you have bloodwhetting or hollowed ground up YOU DO WHAT YOU WANT

[Derio]

If your PLD or WAR it doesnt really matter unless you are in a low level dungeon. The pure amount of mitigation and self healing from those two jobs are so strong you have to have really gear or bad dps like trusts level bad for it to affect your healer.

[Tranquilmelody7]

Sorry,
I was just trying to get
TBN to pop.

[DanielNegreanu_Adamantoise]

Sorry,
I was just trying to get
TBN to pop.

[Marxam]

In trash pulls in dungeons there is no reason to not move out of AoEs. Like you said nothing has positionals so you aren't affected by that so there is no real need to ever eat AoEs on trash.

For bosses it 100% depends. Zodiark EX I will intentionally eat every AoE that pushes me out of melee range since nothing in that fight hurts enough for me to care and I can just heal myself back up to full anyway. For fights that give damage downs for debuffs instead of vuln stacks I will avoid every AoE to keep from getting that debuff.

Also don't forget, ALL tank aoes are circular so you are actually missing enemies by moving out of the center.