Another thing to keep in mind is that more involved healing doesn’t necessarily have to mean just hitting the Cure button more often. I’ve never played WoW, but I played several healers at pretty high levels of content in Everquest II, which is a similar type of game in many ways to WoW and FFXIV, and one thing I noticed from there that I really don’t see here is a variety of utility spells on healers.
In FFXIV, you’re pretty much either direct healing, including specialty heals like regen, or DPSing, without much in the way of debuffs/buffs/status cures/etc. Status curing, in particular, is potentially a great way to add more depth to healer gameplay without just reducing potencies on the green-numbers spells, but I’m not sure the basic spell infrastructure is in place to support it. We really only have one cleanse—Esuna, with its limited applicability, zero recast time and single debuff removal—which doesn’t give a whole lot of room to be creative. It also doesn’t give much reason for other roles to want to slot their own status removal abilities (mage DPS with Erase, for example).
My Defiler in EQ2 had a single-target cleanse (basically the equivalent of Esuna), an AoE cleanse with a much longer recast time, and a “special” cleanse with a very long recast time (in FFXIV terms, consider it like being able to remove certain single-target boss mechanics like Prey, Earthshakers, Shriek, etc.), and other healers had generally the same setup but possibly with class-specific variations like a total cleanse, each with power-appropriate cast/recast times. That setup forced meaningful choices, and also interactions between the healers in a group, that went beyond coordinating heals. You had to decide whether a particular debuff was worth burning a high-cost or long-recast ability to remove, and consequently risking not having that ability for something else. Do you burn your curse removal for Twintania’s fire prison, knowing that means you’ll have to heal through the Death Sentence debuff, or do you accept the downtime on one party member and needing to DPS the prison in exchange for being able to remove the healing debuff later?
There are other complexities to the healing kit that could be considered as well, like maintaining temp debuffs and party buffs or handling mechanics—either accidental failures or deliberate setups—via death preventions; imagine if you lost the ability to use Swiftcast on Raise, but in exchange, you instead had a short-duration, long-recast ability that would 100% prevent the next instance of damage on a party member or instantly heal them up to 50% the next time they dropped to 0 HP in a given time window. The ultimate effect is similar, but it shifts the emphasis from reactivity to proactivity. On the buff/debuff side, a mix of indefinite upkeep effects (along the lines of how Miasma used to apply a healing debuff, but actually meaningful) and comparably short-duration, high-impact effects like AST cards could provide a similar level of activity to what we have now while still shifting emphasis away from spamming DD spells.
All of this could be done in addition to the straightforward “make HP go up” type of healing, but it would require investment in the form of new and modified spells, as well as more fundamental systems-level changes (for a start, make debuffs more prevalent and meaningful—give regular dungeon bosses debuff-inflicting attacks on the level of pre-nerf T7’s Venomous Tail). I really do like the idea of being more than a green DPS, and the one-dimensional healing mechanics are one reason I don’t play this game all that much any more; at the same time, I’m also not sure that the complexity of healing in a game like EQ2 or, from what I hear, WoW is achievable within the bounds of where SE seems to want to keep FFXIV (and, as noted by several people, it’s not really something that applies to existing content).