Let me regal you with a recent tale of Aurum Hell with a newbie WHM. I want to preface this and just say that I don't fault the WHM in this but moreso the Tank but whatever. I'm only saying this to just say how bad WHM has it at low levels.
So, leveling roulette lands me in Aurum Vale the other day because ofc it does. It's a GNB, MNK, WHM and myself as BLM. The first area and boss are uneventful. It was the pull just before the 2nd boss that things go south. The Tank decides to grab everything right before the boss and that didn't go so well. The WHM had Regen going and was spamming Cure 2 until they got dangerously low and had to use Cure 1. The Tank was popping mitigation but we still ended up wiping (think they stepped into a puddle and took too much damage IDK). We try again but the tank is insistent on pulling everything again. It was slightly easier since some enemies had died but the WHM was low again on MP by the end. 2nd boss was uneventful but afterwards the Tank once again decides to pull everything up to the wall. We miraculously didn't wipe this time but only because the WHM ended up using rescue on the tank to pull him out of range of all the enemies for a moment but still, their MP was strained. The WHM and MNK ended up dying to the last boss due to getting hit by bad breath at 20% or so but the GNB and I were able to survive long enough to kill it.
Now, the WHM did EVERYTHING in their power. They used PoM, they kept Regen up, they used Cure 2, everything but it came at being bottomed out on MP every time. Now, obviously low level content, especially dungeons, isn't really cause for alarm because its irrelevant now but what do you think that WHM player felt like going thru all that? They were in level appropriate gear, having gotten every pieces of the 1st WHM artifact gear (minus the shirt obviously), using jewelry that ranged anywhere between 28-47 with a level 41 weapon. They had used what few CDs they had available and was actually able to hold it together for that 2nd pull but only by the skin of their teeth. That couldn't have been fun to experience, especially for a 1st timer in arguably the worst dungeon in the game. I felt terrible for them having to endure that. Sure, we can blame the tank for it but like, it would be disheartening to say the least if you did everything right and still had a hard time.
I really wish that WHM (and healers in general) got a small overhaul to their starting toolkits so that experiences like that wouldn't really be so difficult for new players.