How DPS complexity can make healers more forgiving

[AmiableApkallu]

Dosis -> Dosis 2 -> Dosis 3
This is your Heated Split, Slug, Clean Shot filler rotation.

Dyskrasia -> Toxicon
This is a 1-2 AOE combo (like Tanks have; I realize MCH doesn’t, but roll with it).

I suppose my question is: What's the extra gimmick associated with these combos -- whether it be resource generation, buff/debuff management, positionals, etc.? Because while I'd take some modicum of mechanical complexity over what healers have now (and the variation in sfx and vfx), I'd still be left wanting for something to manage and be making decisions about, or even simply the illusion of such.

It's the extra gimmick that makes a combo what it is, and not just 1-1-1 split up into three buttons instead.

Why CAN'T we have one that fires off a combo like MCH

For example, MCH's combo builds battery gauge on the third step, and only the third step, and tank AoE combos provide something extra on the second step (Divine Might, Surging Tempest, Blood Gauge, cartridge).