This is correct.

The main problem with the role action system is that it doesn't adhere to a clear design objective. Is the goal to avoid duplicating essential role abilities, like Rampart and Provoke? Or is it to allow fight-specific customisation, by letting you choose to slot in Low Blow or Interject?

The problem with any system with optional 'builds' is that there will generally be a best choice. You see this in games with talent tree systems. That being said, there need not be a "best" solution for every scenario. Do you need a Silence or Stun? Do you need a PBAoE enmity grab, or one that acts at a distance? If you really want to build up a system that allows for customisation, you need one which makes you choose between related abilities. You shouldn't be choosing between Rampart and an interrupt. Rampart will win out every time. You should be choosing between two types of situational interrupts. This is one place where branching talent trees excel.

Another problem that arises in designing a customisable role-action system is that some jobs have similar abilities built into their baseline toolkit. PLD never really needs to take Low Blow because they always have access to an on-demand stun in Shield Bash. Likewise, most tanks will slot Reprisal for raid content, but PLD and WAR also have baseline access to abilities Veil, Passage, and Shake which can be used for additional raid mitigation. If the point of Reprisal is to give every tank equal access to raid-wide mitigation, then Veil and Shake shouldn't be job exclusive. They should be role actions as well.

The final problem is that the transition from the old cross-class system was poorly executed. At the end of it all, some jobs, like WHM and DRK, were left with fewer job actions than others. Given that the cross-role actions are no longer attached to any job, these jobs will permanently be left at a deficit in future expansions unless they are appropriately compensated. The implementation left many players with the feeling that their job's unique abilities were 'stolen' to be redistributed to other jobs.

I think if the goal is just to standardise a set of abilities across a given role, then the easiest solution is to just remove the element of choice and give everyone a fixed set of common abilities. But I would be partial to a talent-tree based system that allowed you to apply traits to a standardised set of abilities. Let players choose between a short recast AoE Provoke and a long recast ranged one. Pick the interrupt of your choice, silence or stun. Choose a damage down debuff on a shorter recast or a group shield on a longer recast. Perhaps pick between a recast reduction on your gap closer or a Tempered Will styled knockback negation move. Break Rampart down into a choice of a physical defensive and a magical defensive.

Alternatively, allow for cosmetic variations in abilities based on job, such as the old Shadowskin animation. Sort of like the Major/Minor Inscription system.