What has happened over time is that the role of healer has been eroded over time, because players keep trying to green DPS with them. So with this many poorly performing healers, SE's response was to lower the healing requirements by buffing the tank's enmity control.

Remember how casting any group heal would rip the enmity off the tank? Remember when casting regen would rip the enmity off the tank? Remember when there were debuffs you had to cleanse instead of heal through? Remember the ill-designed Cleric Stance that made players rip your face off if you used it? All that went away with HW.

Healing before HW was "healers should heal, and not DPS" and anyone who did otherwise was playing poorly. Then by Stormblood, the healing requirements were nerfed to the point that you could quite literately sit out boss fights in story content if the DPS don't step in any bad. I've pointed this out on streams where I'd sit back and watch the NPC players do the entire fight. That should not be a thing. The NPC DPS players have perfect positioning because they are scripted to.

The pendulum has to swing back the other way, where monsters and bosses cast cleanable debuffs that last the entire fight if not removed. Where a combination of the tank mitigation and a group heal afterwords is required. There are enough ways to overheal 8-player content. One healer with shields and one healer with regen was always the preferable thing. Nobody is ever sitting there casting esuna, because anything that needs to be cleaned, doesn't exist. Only the Teratotaur in Qarn ever made Esuna required for a fight. We've never seen this mechanic since. Likewise the "sleep" spell, it was only "required" for Brayflox Longstop, and even then people just faceroll past this now.

Healers utility is basically next-to-worthless, and any casts we had for utility no longer exist anyway. Remember "Water", remember what Water was for? To push the mob back. Tanks got (rightfully) annoyed with it sending monsters all over the place. It was a very useful skill when playing solo storyline ARR content, but it was made all party content frustrating.

And then you have players who think that if you don't use every single skill, you're playing wrong. Which leads back to all of the above, where casters use skills that are either not needed, or should not be used in party content, and likewise skills that are kinda redundant for playing solo content. Healers could pretty much do all ARR content without Cleric Stance turned on, but it took 10x longer, and you had to use things like Sleep and Water to be able to actually defeat things. That's no longer a thing. If you turned cleric stance on, then your heals did pretty much nothing, so you'd just die frequently in solo content.

I don't want to return to a time where "Cleric Stance" made healer play frustrating because of the two factions of "healers must only heal" and "green DPS's that never heal", what we have is a compromise where players can choose to heal or DPS as much as they are comfortable doing. But this seems to just keep leading us to content with barely any critical healing components, which makes you wonder why you have so many healing kits.

Just don't add more DPS complexity to healers. If you want to play healer, play a healer. You get your one AOE, your one DOT, and your one single target attack. You need nothing else. Leave that complex DPS stuff on DPS. They gave us Sage because of the amount of people who want to green DPS.