Concerns about " Getting rid of unused and ineffective actions"

[LineageRazor]

Cure III is godly in very niche circumstances.

For example, in A4 when you had to spread out far from the other heal and away from the group, and the tank would be constantly hit with splash damage on the melee. Cure III is meant for that. It's also very useful in T11. It's also a much higher potency than Medica, making it better for topping up the team after a huge aoe (assuming you have a coordinated team that stacks up for said attacks).

Nidhogg's Akh Morn spam is an even better example! A WHM should definitely use Cure III over Medica in that situation (after an initial Medica II, at any rate).