Red Mage could use some help.

[Cynfael]

They don't balance off of ease of gameplay, Yoshi-P is on record saying as much.

Exactly. If they balanced RDM based on ease of gameplay, we would probably be using Verflare to blast collectibles out of Lush Vegetation patches.

Joking aside, Galvuu is right that difficulty is highly subjective. I imagine that players who aren't accustomed to proc-based gameplay find RDM to be stressful, while those of us who were BLMing it up in 2.x find RDM to be kind of nostalgic (at least that's how I see it, and I actually enjoy RDM specifically because it reminds me of the old BLM playstyle, which I admit to enjoying despite its bare-bones simplicity).

At first I didn't agree with SE's intent not to balance Jobs with estimated difficulty in mind, but it's probably a good thing for the game if a wide variety of Jobs and mechanics are available and also viable. Playing a mechanically complex Job well should largely be its own reward, and it's also less messy when SE doesn't try to impose its opinion of which Job is the most or the least difficult.