Job identity is pretty much dead. Everything has been homogenized so much in the name of balance that any uniqueness and individuality between jobs is almost non existent.
Tanks are a perfect example here. Where the game began paladins had the identity of defensive fortress style tank. While warriors where the brutally offensive orientated tank.
As the game has progressed though there's almost nothing that separates them. Plds can do as much if not more dps than warriors can. Warriors can survive all the same tank busters a paladin can. They nearly always share gear which in turn means they're defence and stats are the same. They've been balanced so much that they have no identity anymore. Dark as well.
Healers as well. Every one can heal just as well as the next with very little identity setting them a part. They tried to make whm a pure healer but that didn't work cos that extra healing power just wasn't necessary because balance means sch and ast also had to be able to cope. So again healer identities are gone.
Dps again much the same. On the most basic levels virtually all dps bring the same to the table. Every dps has some form of aoe attack. For example you don't have an aoe king that sucks at single target. Or a single target king that sucks at aoe. Now every melee has access to goad and invigorate natively. Goad being one tool that set a ninja apart now homogenized to all melee.
It's the idea of balance and homogenization that every job has to be perfectly viable in every situation that completely destroys any real chance of job identity.
The only real difference between melee for example is the weapon they hold.
This is also why crowd control has never been utiisised in this game. Silences sleeps binds heavy stuns all exist but have never been utilised.. Throughout 2.0 and 3.0 they were only ever used as a dps increase. And never touched for there actual effect. So those unique elements jobs bought to a party were never actually used.
I cannot tell you the last time anything actually "had" to be slept for example. or bound in place by a bard. none of those things even though they are in the game have never been made use of because of balance.. and that's why job identity is gone.