The overhaul I suggest would introduce ramping and healing rotations to healers, similar to how SAM ramps up to a Midare/Tsubame, Instead of having powerful healing spells available 24/7 like Medica 2/ Medica and Cure 3, the healers would have to do their healing rotations properly in order to gain access to those spells. It would require you to think about healing itself, rather than it being an afterthought like it is now (and it always has been) wherein you optimize your dps more and you relegate your healing abiltiies to a spreadsheet; And this will in turn make healing engaging, because everytime you have to think in a video game is the time where you are engaged.
A good example that I have is Disc Priest healing in a raid setting, wherein the spec heals through the buff called Atonement that lasts for 18 seconds, as 40%(give or take) of all damage you deal to a single target would be transferred to anyone with Atonement as healing:
Weak single target heals would apply as much Atonement to as many peopel as possible without the buff running out
Power Word: Radiance(can only apply Atonement to five people and you only have 2 charges every 20 seconds) would be used to apply Atonement to everyone else
then you use a cooldown to extend/buff Atonement or you forgo it completely for an emergency ramp
then you DPS the living shit out of the target just so you can heal everyone through the massive multiple raid wides that are coming out.
It's simple in concept yes, but there's
multiple ways to fulfill every single step in that series of events,
including the DPS portion.
That's what I think the game needs for healers. Engaging healer-related gameplay that's not simply just "extra DPS buttons", and that's what I personally want in a healer overhaul.
And frankly I don't think this is feasible as it will need every encounter in the game to be reworked, and will result in everyone else to be too scared to heal resulting in lower healer numbers.
A lot of people would complain about this, not because it's less engaging, but simply because it's too hard.