Sorry if this sounds mean but this is truly one of the scrubiest takes I have ever read.
HC Dungeons are so easy i’m pretty sure if your Tank doesn’t use a Single Mitagation the entire dungeon you still wouldn’t OOM as Healer.
Optimally healing usually means you stay Mana positive or Neutral. You have loads of CDs to make your healing more efficient and ways to Regen Mana and stay Neutral/Positive.
I think most good Healers can stay mana Neutral in HC Raid fights outside of the big Raid AoE Damage phases, to give you some perspective.
Cata is the first Expansion where healing Gear matters so this issue could be a slight gear issue but i’m willing to bet you don’t play your class optimally or understand the healing priority rotation or cooldown management.
A good Healer will never ever need to Drink in a HC Dungeon and if they did, they would run with the Tank and only drink before combat starts so you are a maximum of 20 yards away and you can stop drinking when you need to cast a Heal so the DPS and Tank never need to stop and wait for you.
In Vanilla and TBC where you couldn’t stay Mana Positive good healers did that so you never needed to wait. You would drink right beside the tank the second he pulled so you would get 30% of your mana back before each pack of mobs and if you did this optimally nobody would have to wait.
This is my advice to you. In every MMO I have played, FF14, WoW ERA, WoW TBC, WoW WoTLK, WoW Cata, WoW Retail, having to wait for the Healer means the healer is extremely bad player, a brand new player(like first month playing a MMO for the first time) or has some sort of disability.
Do some self reflecting on what you could have done not to make the group wait because with the current populations gaming skill, its pretty universal and standard in PuG Heroics you don’t ever need to stop and wait for the healer to get mana and its the same with every other MMO on the market now.
I really hope you read this and take this advice on the chin because you don’t understand how bad your take is.
Its the equivalent take as me as a DPS saying ah I didn’t kill the boss because the other DPS did 5k DPS and we wiped. Instead since I’m good player who understands my Class I just Pump 40k DPS and do 90% of the bosses Health Solo and don’t rely on anyone else to do the damage/mechanics.
Go read a good guide like wowhead and join class Discords for your spec. If you dp this you’ll 100% start to see your scrub take on this situation.