Every job has its niche really.
DRG brings battle litany and piercing debuff for the ranged DPS.
NIN brings slashing debuff for tanks, WAR in particular.
MNK can save DRK from wasting Potency by applying INT debuff.
SMN is just great utility and DPS all around.
The only job I find doesn't bring much to the table is BLM. Even back when flare was still relevant.
