But I don't think it's meant to be a healer like the other three.

From the get-go of the original rework it always seemed to be designed as a glass-cannon that was meant to apply shields and "stall" rather than heal; hence the nature of it's LB. The minor heals from landing Dosis aren't meant to do more than a minor sustain, and the main draw is putting up Diagnosis shields after using Eukrasia, because a fully used-up shield buffs your next Toxicon damage.

If you can look at it as more of a DPS (like it's designed to be) with minor heals as a byproduct of its kit, then it's actually very solid. If you want something with spot heals and other abilities to restore HP... that's what AST and WHM are for...

I know people like to hyper-fixate on the PvE trinity roles, but for this current iteration of PvP it's more important to identify jobs more by the archetype playstyles they're designed around.