This guy gets it.This is just my two cents...
But I think the fact that this is even a question is the same shortsightedness that brought us BLU. BLU “can’t be balanced for content” NOT because another caster couldn’t inherently be balanced, but only because of the spells that the devs wanted to give it. If you give a caster a potential AOE Benediction (White Wind) of course it will outheal healers. If you give it a spammable tank immunity as long as it has the MP (Diamondback), of course it can align itself with tanks. If you give a caster spells that have majorly elemental and status affinities, of course it won’t work well in current content with the other 17ish classes who have been far removed from elements and status ailments over the past few expansions.
This is the same issue we encounter when we speak about any other role, but especially about a new healer since this is always the excuse we are given: “it can’t be balanced.” Yes, a new healer can’t be balanced and won’t work if we continue talking about designing it the wrong way. For example: we don’t need another shield healer or another HOT healer. We have 2 of both already because of AST. The new healer can and should have an entirely new healing niche. Many new niches have already been discussed ad nauseam on the forums already; life stealing healers, chemist healers, healers that store overhealing for later, maybe a debuffing healer for damage mitigations, etc.
The second reason we must rethink a new healer requiring a new niche has already been mentioned as well; shields don’t stack and therefore another shield healer limits which party compositions can be efficient and limits healer synergy.
Balancing a new healer, as theorized my mind, has always been possible. I just don’t think we will ever get anywhere basing a new design first and foremost on what we already have.