Problem :On a good day with a good team in most instances you will not but doing much besides 1-1-1-1-1-1. tank busters are a joke, raid wides are infrequent, mechanics revolving around healing is slim to nonexistent. On a bad day with a bad team youll at most do some ressing or healing slightly more than continue 1-1-1-1 Due to this gameplay the question is irrelevant due to the jobs being irrelevant. Doesnt matter how complicated the kits are, you can get by raw healing medica 1 and cure 1 and its equivalents for 99% of the content. Except savage which is where all jobs are designed for no matter how few of them their are. Not helped by some job skills being outclassed or never used to due how many tools healers kit. Secret about me is as a SGE ive never used; Kardia, Soteria, Hamia, Panhamia, Zoe, Pepsis, Diagnosis, Prognosis, Kerachole, rhizomata, Holos, & Krasis due to never needed too and all healers have this fluff issue. In dungeons specifically if your with a WAR you dont even need to heal. Bosses are a bigger waste of a healers time because nothing is thrown to warrant your existence due to trivial mechanics. Trials could be fun with 1 healer but with 2 its plainly overkill back to 1-1-1-1 and doing 2/14 healer actions.

Solution The biggest naysayers are raiders for a job overhaul with some exceptions. For dungeons; mobs needs more diversity than bowling pins, vague answer but dont wanna rant on dungeon design again going off topic, Dungeon bosses need to do more damage and need more mechs where the party takes damage, all bosses need this change 24 man raids and nm trials dubbed raids included

ask again once the game uses healers in their day-to-day content using at least 50% of their kit vitally