Just a rant, TLDR at the bottom.
Why are so many people on this subreddit downplaying the healer role? Ever since the dungeon update happened. A lot of healers come out and state that they won't heal because of it, or when people point out that there's a healer shortage, I keep seeing comments like, "It's low level, you don't need to spec into healing," "A Ret Pally can heal just as well as a Holy Pally," or "You can heal most dungeons fine as an off-spec until 60."
Healing, even in retail, has always involved some kind of mana management. Sure, DPS classes have access to healing spells, but how many times can you actually cast them before running out of mana? For most classes, not very many. Paladins and Enhancement Shamans, for example, don't prioritize Intellect as their main stat, meaning they'll burn through their mana after just a handful of healing spells, and you'll just have to sit there watching each of your team members die out.
One of the main reasons to spec into healing at lower levels is mana efficiency. And please, don't tell me to just use Rank 2 instead of Rank 3 to save mana. Two Rank 2 heals provide roughly the same healing as one Rank 3, meaning you're spending more time casting for the same result.
For everyone claiming you can heal any dungeon before level 60 without specing into healing, please give it a try and upload the run to YouTube. I'd genuinely love to see how you do it because it can be a great learning experience for healers who play this game.
Even HOT at levels 13–15 can be rough for healers. At that level, most healers have access to only one Rank 2 healing spell, and there are mobs in HOT that deal AOE damage that can potentially wipe the entire group if people aren't positioned properly. Now imagine trying to keep everyone alive with less than 500 mana because you lack the appropriate talents and Intellect gear.
If we're already dealing with a healer shortage, why are we discouraging people from playing other classes as healers by pretending the role requires little to no investment?
Please stop making tanking and healing sound easier than they are. These roles are already hard enough to fill without people dismissing the challenges that come with playing them.
TL;DR: Just because a class has healing spells doesn't mean it can effectively heal a dungeon. Mana efficiency, talents, and Intellect matter even at lower levels. If you think any class can heal dungeons just fine without specing into healing, I'd love to see you prove it. We already have a healer/tank shortage, so let's not pretend these roles are as easy as some of these comments make them out to be.