Oh goody, this is the part where non-healers who occasionally cure-spam their way to a free carry through fights get pedantic and pretend that AoEs and one-minute oGCDs are a meaningful part of a single-target damage rotation.
An oGCD you mindlessly smash on-cooldown for the DPS, a single DoT, a damage spell that exists only to ensure that lily heals are DPS-neutral, the one button you'll press for 60-90% of the fight, and your one AoE spell that you'll never use in single-target situations.
This reduces to two buttons being used for the majority of your GCDs.
An oGCD that exists solely as an Aetherflow dump, a single DoT, the one button you'll press for 60-90% of the fight, and your one AoE spell that you'll never use in single-target situations.
This reduces to two buttons being used for the majority of your GCDs.
The one button you'll press for 60-90% of the fight, your one AoE spell that you'll never use in single-target situations, a single DoT, an oGCD that you'll mindlessly smash on-cooldown for the DPS, another oGCD that you'll have to hold for specific mechanics it can delete with its healing (P3S comes to mind), and an oGCD that you'll sometimes get to weave at random once or twice a minute.
This reduces to two buttons being used for the majority of your GCDs.
The one button you'll press for 60-90% of the fight, one AoE spell that you'll never use in single-target situations, a single DoT, another AoE spell you'll never use in single-target situations, a third AoE spell you'll never use in single-target situations, and which can only be used if one of your shields breaks, and a fourth AoE spell stapled to a heal with a high MP cost.
This reduces to two buttons being used for the majority of your GCDs.
BLMs can choose to RP as Ice Mages and ignore half their kit as well. People seem to get a bit cross when you do that in dungeons, though.
Healers should not only be fun if you deliberately gimp your own performance.