Would like to see more shared skills that are useful

[Deifact]

SE developed NIN as a DPS, and SAM as a tank. So there's that.

Then there's the whole series of BRD and DRK tanking that wasn't intended, and before the mazurka hate nerf, RDM/BRD chainspell mazurka tanking was about the silliest thing ever thought of for xi.

Exactly this. Even the illusion of choice gives way to new strategies for different fights and situations. And finding these combinations of skills and abilities in itself adds something new to the game.

Not having a choice at all will always be worse, sure it makes it easier to balance for the devs, but they're still doing a terrible job at that with job stacking on certain fights.