I'm no super-pro PLD, but
I asked the same thing when re-gearing mine several months ago. Basically, it's SUPER niche but has some minor uses like Chivalry (MND).
Across my two characters, it's literally the only one of the 22 jobs where I didn't get a +1/+2 JSE neck. I'm actually out of stuff to augment in Dyna these days on my main so looked at it again recently just to have something to work on, and I just couldn't justify the cost.
Between your other options like Moonlight, Unmoving +1 (HP), Loricate +1... there's just really not much of a need for it.