Let's all assume for a moment that classes ought to be simply removed. Would anything replace those aspects? You've gone from near-zero healing on caster classes to truly zero, removed the majority of (extra-rotational) burst options from all but Bard and Dragoon, wasteful but high-enmity add-grabs from melee, taunts from non-tanks, and enmity management from casters. Does any of this help gameplay?
Now, we could go instead we could revamp the jobs to include similar functions in a unique way. BLM might take Umbral Shroud to temporarily release enmity and generate less over the duration and, alternatively, modifying other abilities, like Ley Lines, to pool duration for upcoming burst needs would remove any ostensible need for Raging Strikes. Similarly, Blood for Blood has never especially been that significant over time nor especially interesting outside of its syncing with other abilities; I'd see that as a reason enough for now to keep it, but in the long run would expect such abilities would be among the first trimmed...
But let me present an alternative. You revamp the classes, filling out more of each class's gameplay and identities through mechanical traits, which can then be cross-classed. Each class gets, say, 5 traits. Each job brings in 2 more. Each class at level 60 can take on 8, while having access to the majority of other class's traits cross-class. Each job can take on 7, with fewer cross-class trait options. Now, by combination of gameplay-affecting mechanical passives, you might just have a Gladiator who is both highly customizable and therefore distinct from a PLD.
In my honest opinion, it's not the classes that are holding us back, or even any adherence to a class system. It's the adherance to a specific number of stat-increasing traits, the exact same number of traits and abilities given to each class, the exclusion of job traits, similar arbitrary but stubborn rigidities, and the complacency to scarcly differentiate classes integrally—in their gameplay, in their undermechanics, etc.—that cut short any future development.