I fully agree and playing WHM in dungeons makes that very clear. If you want to weave anything between Holy III spams you gotta do it the old ShB way of using Lillies or Swiftcast. Doesn't help ofc that between Thin air getting split to two stacks, Beni getting a second stack and getting aqua veil WHM got a whole lot more to weave now than in ShB but at least Afflatus is a double weave window and not DPS negative in dungeons. Still feels bad not being able to slidecast with Holy to dodge AoE's.
They really haven't updated the healers well for that GCD nuke change. It's a great change for mobility but now the previously dedicated Weave/mobility skills feel a little out of place.
So the solution is to just not GCD heal at all because its a hard DPS loss. Going oom in 10-ish GCD's would punish GCD healing spammers which already disincentives GCD spamming enough by itself. Besides i feel like you're overselling Cooldown management. If unavoidable raidwides come up every 30s people will just throw out Ixolche / Fey Blessing or Indom / Afflatus rapture / CO or Earthly on cooldown. If tank busters come up every 60s people will just use Exaltation / Aqua veil on cooldown. If Pushback mechanics come up every 120s people will just use Surecast on cooldown. Incredibly engaging gameplay. This might be more dire in Savage fights but 80% of content in this game isn't savage and only roughly 10% of the playerbase even does Savage raiding.
So it's better to make GCD healing not optimal so you can ignore 33~50% of your kit instead. I really wanna play a DPS where ignoring half of my rotation is optimal gameplay.
The same can be said about oGCD healing. Just pressing a button in between your Nuke to heal without consequences is boring asf. at least in ShB you had a rougly 75~90 potency to pay for that but not anymore. Giving us a more elaborate DPS rotation might fix this but right now both healing styles aren't engaging. Right now if you want to be a proactive healer your options are Damage mitigation oGCD or a 2m cooldown barrier oGCD. The main meat & potatos of proactive healing, applying Regen or Shields before AoE raid wides to mitigate damage is disincentivised even though it forces you to pay attention to what the enemy is casting, which you could argue is more engaging. And people have argued that since Tankbusters got a visual indicator. I'd rather GCD heals aren't dead weight in our toolkits and be usable without being punished so heavily than focus entirely on reactive oGCD healing. And i firmly believe that GCD heals being MP negative would be more than enough to disincentive people from spamming them by itself.