One good thing about role actions is they ignore level sync. Whether that outweighs the benefits of having unique actions I'm not sure, but neither are particularly detrimental as they are.
There's benefits to having some consistency in skills such as Reprisal, Feint and Addle, so that its easier to track debuffs, and it's nice to have some 'basics' that don't change between jobs that you can fall back on in low level content, like Second Wind and Peloton.

You could go the other way and add in high level role actions to take advantage of this further.
For example; Troubadour, Tactician and Shield Samba all do the same thing, and while it's nice that each job has it's own version and animation, nothing would be lost if they were all turned into a role action, which you learned at level 60 but could be used in lower level duties.

Perhaps instead they could make it so that all Class abilities ignored level sync. This would mean that once you reach level 30, that's the minimum kit you'll ever take back into level synced content, and then throw in a few odd class abilities above level 30. The issue here of course is jobs that don't have base classes. So I guess that's why we're still relying on job actions.