Either take away the healing powers from tanks or give healers tanking powers.

[Carighan]

IMO they just need to look at why other MMORPGs don't have this problem. And it's simple: They cause far far FAR more damage to the groups than FFXIV does.

Bosses fling random 20%-40% HP hits on people into the raid constantly. AoEs pulse every few seconds, not every 60 seconds. And while they're not as strong, they're constant and together with the single hits require constant GCD casting of both single and group heals. Ground effects that cannot fully be avoided. Damage on attacking the boss with each attack. Random line AoEs with no forewarning.

There's a lot to heal in other games. So much that whether spamming your filler damage spell is boring or not is frankly not worthy of discussion: You're busy healing.

Give me that! I play a healer! Make a Paladin happy he's actively healing, but well, he's casting medium-size single target heals, that's all he can do, he can spot-heal but not keep a group alive. He should not be able to, due to the raw and constant stream of damage coming into the group! He could save me, and that'd be useful, as in turn I can save him and the other two (or 6). That's how it ought to work!

(edit)
It's also a bit unfair to say "tanks". Paladins can cause some healing, but while it's a lot it doesn't last long. Gunbreakers and Dark Knights are mostly SOL. It's only Warriors that are flat out overpowered in healing, and just need a nerf. Say, let them have stackable shields instead. This gives them the same raw effective-health output, but the inability to at all re-heal any damage taken means they cannot keep people alive on their own at all any more.

[WeakestZenosEnjoyer]

It's also a bit unfair to say "tanks". Paladins can cause some healing, but while it's a lot it doesn't last long. Gunbreakers and Dark Knights are mostly SOL. It's only Warriors that are flat out overpowered in healing, and just need a nerf. Say, let them have stackable shields instead. This gives them the same raw effective-health output, but the inability to at all re-heal any damage taken means they cannot keep people alive on their own at all any more.

Paladins match WAR healing in single target when Bloodwhetting isn't just Benediction, it's still a problem, just currently overshadowed by how stupid Bloodwhetting is.

Gunbreaker straight up has excog for some reason and can now amplify it but without Excog of Corundum they're fine, Aurora and Brutal Shell is not soloing any serious bosses.

Dark Knight is considered to have lower sustain than all the other tanks for a reason, they're actually in a good spot and other tanks should be lowered to it. (Also, TBN is exactly what you said for a WAR nerf, barriers don't re-heal existing wounds so TBN can't be your sole sustain tool like the other short mits and they're really helpful for big high-end tank-busters.)

[Silver-Strider]

Paladins match WAR healing in single target when Bloodwhetting isn't just Benediction, it's still a problem, just currently overshadowed by how stupid Bloodwhetting is.

Gunbreaker straight up has excog for some reason and can now amplify it but without Excog of Corundum they're fine, Aurora and Brutal Shell is not soloing any serious bosses.

Dark Knight is considered to have lower sustain than all the other tanks for a reason, they're actually in a good spot and other tanks should be lowered to it. (Also, TBN is exactly what you said for a WAR nerf, barriers don't re-heal existing wounds so TBN can't be your sole sustain tool like the other short mits and they're really helpful for big high-end tank-busters.)

The problem though is that, historically, SE can't keep up with their own nerfs and buffs with any reasonable level of consistency. They nerfed MNK's Mantra last expansion from a 20% Heal buff down to 10% just to go around and grant them the kind of ridiculous AoE Heal that is Earth's Reply this expansion, thus totally negating the nerf in the 1st place. The whole point of the nerf in the 1st place was because BRD's Nature's Minne was originally a ST heal buff for 20% so Mantra was just straight up superior to it so they changed Nature's Minne to be an AoE and changed it from 20% down to 15% to make it just better Mantra. So, if they're going to repeat that same mistake, the next step would be to add an AoE heal to Nature's Minne, wouldn't it? And if they do go that direction, isn't it also in the realm of possibility that other underperforming jobs will get similar treatment? TBN doesn't heal now, but there's nothing saying that they won't add one to it later on down the line.

It's a slippery slope that needs to be addressed before it can get even worse.