Thank god this isn't remotely true for FFXIV. Healers are the hardest role at the highest difficulty, since they are literally required to contribute damage in addition to heal AND frequently have to do mechanics at the same time. DPS are usually responsible for MOST of the mechanics, and if any of them do die, even if the next mechanic isn't an instant wipe without a full party of living bodies, their damage gets nerfed by 25% and you lose to the enrage timer.
Easiest job in FFXIV is off-tanking. You're pretty much a retarded dps with easier combos. Unless you're a paladin, then you can throw out a shitty healing spell about once a minute.