However all this said going back to your original question what is job identity? It boils down to what does each job do that makes it unique from every other job. And in PVE it's mostly aesthetics. There is very little deviation.

In PvP however there is a LOT of deviation. Down to defensives that grant damage shields and boost defense, AoE stuns, draw-ins/knockback, HP sacrificing attacks, GNB draw changing skills in your kit based on what role you used draw on, polymorph, AoE invulns, attacks that render you invulnerable to damage, true stealth and Death Link, Counter Attacks, delayed damage, fear effects, aoe buffs, crowd control, charm, stance swapping among others. Not to mention personal Limit Breaks that gives every player their own moment of glory and satisfaction. Which all serves to give these classes the identity players are looking for.