I'd disagree. Lumina's support is split up into 2 parts: Healing and Buffing. The buffing part is out of the window by rifts and wells existing, as covered extensively already. The healing part, which, indeed, is a classic RPG support trope, is not relevant the way it is implemented into Lumina either. Lumina provides a short burst of health and immediately starts health regen on the affected target with the Noble Round itself, usually, being enough to top an ally off. The issue lies with the TTK of guardians VS the TTK of other RPG characters. Ironically, guardians are fairly short-lived and can't take a whole bunch of damage until they die and in high-end encounters, in which such healing would be required, a guardian can die anywhere from 2-0.5 seconds. This is a TTK that is way too short for the type of healing that Lumina provides since its healing is neither hitscan nor healing over time that would allow someone to go out of their way to take some damage, because they have a buffer in form of healing over time. In other RPGs, such healing works fine, due to their reduced TTK, where players aren't dying within 2 seconds of not being healed, but also require constant healing to stay up. Heroic Menagerie amplifies those issues even further, where enemies can straight up one-shot guardians, some of them even while inside the well, so mid tree void titans became meta since they can make sure that the team doesn't take damage in the first place while [i]also[/i] providing them with a damage buff that stacks with everything else (i.e. Well) if they shoot through the shield that is protecting them from harm. Lumina's healing isn't working preemptively, like sitting in a well or behind a banner shield does and any form of reactive healing is usually either not required in the first place or too slow to matter by courtesy of how the gun works. I could see Lumina finding use if the damage buff worked together with other damage buffs, buffs damage in a different manner, similar to how arc souls are technically a damage buff but aren't straight up jacking up the numbers on your gun or if it dropped the damage buff aspect entirely in favour of better, more relevant healing mechanics, like a healing over time, over-shields or even something akin to a death prevention mechanic, that while under the effect of a noble round, the ally would regenerate their entire health bar if they fell down below a certain threshold. But as it stands now, with the current way the game plays, I don't see Lumina being a worthwhile addition to any guardian's arsenal. It can be fun, yes, it can be used casually, yes, but pretty much anything falls into those categories for some player out there, which doesn't necessarily make it any good.

I agree with you brotha great post