Much of what made the FF jobs across decades of games interesting is that they couldn't always be pigeon-holed into tank/dps/heals. Some iterations had legitimate support classes that were light on DPS. Without there being at least a 4th role (support, crowd control, whatever), then we'll just get various permutations of DPS for the foreseeable future. Or if not that, maybe a tank that is just as lacking in identity as the other 4.