Another day, another forum/reddit post about the state of max level gameplay in FFXIV, this time focusing on healers. My current theory on why FFXIV is experiencing unhappiness is because the "high skill gameplay" does not match "low skill gameplay".
To see what I mean, let's look at WoW. In WoW a mythic healer plays much like a normal healer, only better. They both cast the same spells, but the mythic healer gets in more casts and triages better. The mythic healer probably makes better use of cooldowns. The normal healer's goal is to slowly refine her gameplay to match the mythic healer.
In contrast, in FFXIV, high skill gameplay and low skill gameplay is very different. If you're in a low skill group, you want to have the tank in tank stance and focus on threat moves. The healer heals more than she damages.
In contrast, high skill gameplay often has the tank in DPS stance, and using DPS stats. The healers are often dealing damage as well, with one estimate of a healer casting 3 damage spells for every healing spell.
I think a game has trouble when you're in the middle, when you're not sure if you should be using the low skill or high skill tactics. You go low skill when the rest of the group is high skill, and they get upset for you wasting their time. You go high skill when the rest of the group is low skill, and you end up wiping.
In contrast, in WoW, how you should play is fairly straightforward. You tank, heal or dps to the best of your abilities. You don't need to significantly adjust how you play.
Another game which has issues with the low skill/high skill dichotomy is Overwatch. Certain heroes are much stronger and weaker at different levels of the game. Widowmaker and other snipers become a lot better when people can aim. Meanwhile, Torb and Bastion are much more potent against low skill players who have trouble dealing with them. But the "meta" is defined by the high skill players, and that can cause issues in low skill gameplay.