So... Dungeon healers is done for?

[Supersnow845]

ACN/SMN (post Lv.12) and RDM (post Lv.64) can already resurrect party members in dungeons, so it's not as if healers have any sort of exclusivity on that.

And a tank that isn't good enough to prevent other party members from dying likely won't be able to keep them alive after they resurrect with minimal HP/MP.

That really doesn’t make anything better

That basically means relying on the competency AND benevolence of the tank to not spend 15 minutes on the floor just because your healer made a mistake