If XIV could take one thing from XI, for me, it would be jobs being unique and offering something specific to a party.

COR being able to bring an EXP buff to a leveling party. WHM being able to teleport a party most of the way towards wherever they were headed. RDM bringing refresh to help people keep their MP up.

The only thing that's even remotely comparable in XIV is RDM being able to chain res for prog.