you seems some important point, First ARR is the relaunch of FF14, second the class was already 50 at the first release... the jobs was added far after (1.21).
we need to be patient to see how jobs will evolve with the increase of level for see if class have any futur...

anyway, for me class are simply the basic and the jobs the advanced progression of your class.... then potentially, yes the class will barely match up with jobs in it speciality.