It was a nice idea in theory (at least compared to cross-class), but horribly implemented due to the mix of 'must-have' and 'next-to-useless' abilities (to say nothing of the stripping of certain jobs only for them to have to buy everything back) ... and ultimately, even now that we can select all 10 (wasn’t this supposed to reduce button bloat?), still does more harm than good...
How so?
1. By making an ability 'cross-role' it means that all jobs of the role have access to it, and by extension must then be balanced around it...
Lucid Dreaming for example, is accessible to all healers and caster DPS, which then forces (for balance reasons) their other forms of MP regeneration to be weaker (than it otherwise would have been), or in the case of RDM, non-existent... and just to make it worse, because Lucid Dreaming is also an enmity drop, but otherwise of little use to BLM, BLM (or any other caster for that matter) cannot now be given their own (more useful and job fitting) enmity drop.
2. All 'similar' Jobs are forced to have the same identity...
BRD and MCH are probably the best example of this… i.e. because BRD is a 'support', with cross-roles for group MP and TP regen, MCH (and any future 'ranged DPS' jobs) are now forced to adopt this ‘support’ identity… and, flipping it around, RDM, which should arguably also be a ‘support’, cannot adopt this identity (or at least not in the same way as BRD) because it is instead a ‘caster DPS’, and it wouldn’t make sense for the likes of BLM, or even SMN, to be given too many support abilities.
3. It makes it harder to balance individual jobs...
One example of this is Low Blow (Tank Stun), which in HW belonged only to DRK and WAR, and had a modest cooldown of 15s (IIRC)…. now that it is a cross-role though it needs to have a longer cooldown (of 25s) lest PLD, who also has Shield Bash, become a crazy OP stun machine... similarly, Reprisal, with it’s now 60s cooldown, can't be made any more powerful for DRK (to give it some needed party mitigation) because then WAR and PLD would also benefit (and no, giving DRK a trait for Reprisal is a terrible idea, because now you have 2 version of Reprisal, in which case why is it even cross-role to begin with?).
4. It robs jobs of what could otherwise be unique utility...
Reprisal would be a direct example of this from HW > SB, but so would new utilities such as Mana Shift... e.g. if Mana Shift were BLM only (and possibly buffed a bit) then it could at least be used as some argument to bring a BLM over a SMN / RDM for raid progression (i.e. more MP for healers)... but because SMN and RDM also have Mana Shift, and (instant) Raise (at half the cooldown, or less) BLM is again left out.
So yeah, IMO cross-role should just be outright deleted and the jobs given back their individual abilities (even if they are exact clones; seriously who cares?), because at least that way jobs can have unique and interesting mechanics / utility, fit their identities properly, and be individually fine-tuned.
NB. And if they want to do customisation in future (which would be nice), it should be done at the individual job level (e.g. selectable traits).