How many times do you have to chose between using a GCD for healing as opposed to dpsing?
How many times does it happen to you, that you have absolutely no oGCD up nor would it come off cooldown in time and have to spend that GCD on healing or someone will die?
I'm genuinly curious because for me, and many others here, this happens so rarely we can go entire dungeon, normal raid and trial runs without ever touching a GCD. Even Ex and Savage is entirely possible without using GCD heal outside of downtimes.

And that is the problem most people here complain about: the incoming damage is pitiful. There is no choice, there is no "I need this megaheal for later, I'll better GCD heal here", there is no healer gameplay to playing healer because we don't have nearly enough to heal while our toolkit gets progressively more powerful and DPS and tanks get more heal/ mitigation aswell while the incoming damage remains the same. There is nothing left but to dps and occasionally pick people up that got one shot.
Because it's either pitiful damage or getting one shot. Constant pressure on healers? Random damage? Having to spend signifcant amount of time on actively healing? None of that.

If you carefully read through the answers you would notice that most here want to heal.
The only problem? There is nothing to heal.
Which leaves us with dpsing.... which is one dot, one nuke.