I can't find any reason to use Barris ever. Back in the day she carried me through GW. Now I just load DPS toons with turn meter. The more damage dealers, the better.
Same in arena. You might occasionally see a Lumi due to her insanely powerful heal, ability block, and OK damage. Daka too, but mainly for stun, and Rez. One guy at the top of my shard uses Ewok Elder, but again for Rez, and turn meter boosting. Heal is just an afterthought.
Protection has mostly killed off healers. You may do OK with them on your arena team against stupid AI that sprays damage, but your team defending with Barriss is effortlessly getting murdered when they defend. As a class they are dead weight unless they do multiple things. Barriss does only one thing, and is just OK at it.