FFXIV's problem is that they take the old formula of turreting classes and then expect them to be mobile. It's kind of a retarded preposition when you think about it. You'll start casting or your melee chain and then AOE time.. run or hide, then hope you can get back on the boss in time to finish your rotations. In some cases classes like BLM or WHM can almost be completely cancelled out in terms of dps or heal effectiveness because of this.
If you look at the last update, this game introduced more AOE in the game just about everywhere that more resembles a Titan fight as normal content. I understand why they want the challenge for players, but you don't give them the tools to effectively to do the job.
I really thought SE would have learned from FFXI about static casting classes after over a decade.
I don't think that's true at all though. You do have to run, but only a very specific times in a fight in general, and at least for healing, there's on very key component to these phases that you don't see in other games: bosses actually cast their spells. They don't just shit a ground marker then a fireball comes out of their ass and hit the ground area while he's still pounding on the tank. No instead he'll turn(or not, that kinda depends), and stops all actions for the cast time, then resume attacking once he's done.
This is a key difference because it means that when you're supposed to dodge, the boss isn't fucking the tank up like crazy. The other thing they do is they only force target one healer out of two, give the boss low damage, or make the movement phase predictable(% or time based) so you can get HoTs/shields rolling on the tank before you have to move.
I've healed Final Coil, and while some fights are very much "dodge all the things", such as T11, none of them actually penalize you for dodging by making the tank dead. In fact in T11, the times when you have to move around is when you get time to catch up on healing, because the boss damage stops entirely for an extended period of time while he does his dodge shit, and you have time to stop inbetween each move to land a heal, plus hots will heal people back up during that time or preshield the incoming aoe damage next.
Other fights have mechanics that simply ignore healers entirely, for example Earthshakers in T13 which forces you to have 2 people dodge shit while taking unavoidable damage, meaning they require healing. Healers never get targetted by those because it'd make the fight impossible since you can't heal yourself and dodge shit at the same time efficiently(not at that speed at least). And while this shit happens, tanks take no damage. Though right after it ends, tanks take a large burst, so you still need to keep an eye on it and make sure he's topped off at the end of earthshakers and if he's not, that's when you burn the instants to catch up. They give you limited tools to deal with movement or mechanics, but they always design the fights with these limits in mind.
Now BLM is a different thing, but BLM is one class. None of the melees have to stand still, at the very worst, they have to position to get max dmg output on that specific move, and I guess monks drop their stacks if they have to dodge for extended periods of time but that doesn't happen very often(and can be worked out via changing the strat slightly like keeping some adds alive during phase transitions)/is balanced by monks superior damage.
BLM suffers on some fights when they get randomly targetted. But that's also why they have the highest DPS out of all the ranged classes when standing still. It actually adds an interesting depth and higher skill ceilling to being a good BLM, if you can minimize the requirement imposed by certain mechanics by good use of Swiftcast, holding Firestarter/Thunder procs, using Aether Manipulation, using Mana Ward or Mana Wall, your DPS will go up and reach a very rewarding level.
I think the game actually mixes it well and has a different take on the dodge all the shit systems. The much slower boss attacks, the larger but predictable hits, the set rotations rather than random patterns for abilities, the damage output being such that a single healer can cover for a short while(or most of it depending), the Scholar having access to a 3rd "healer" that isn't affected by 99% of the mechanics and as such can keep healing at all times, it makes it so there's not really a "bullshit" moment in healing in my opinion. The closest would be lag issues and how playing from europe on top of the typical healing delay means sometimes I see a heal land but it actually lands after the hit on a dead tank or doesn't shield the hit I wanted to shield, though this is mostly the result of me cutting corners with DPS rotations and starting heals a bit late.