The problem with "Instant OFF GCD" abilities makes combat feel less rewarding.

[Raymeo]

You must have missed the part where he's not a Paladin in Final Fantasy XIV.

Oh, so all of that stuff you were saying about the game needing to be realistic is suddenly out the window when I show you that it's not currently realistic. Isn't that convenient?

The tactical nature of the game requires a little more anticipation when casting things like Benediction. You had 2.5s of GCD to realize your tank was going to die. You should have either A. interrupted whatever you were casting to use Benediction or B. Find a tank that can survive more than 2.5 on his own.

Cuz the tank is the only person who ever takes damage. You never see any healers needing to heal each other or themselves, and since that much has to be true, then healers having to cast a resurrection during battle must certainly be a myth as well. Nope, every GCD is used to cast heals on the tank, and if they die then it must have been within 2.5 seconds of being topped off. Therefore a dead tank always means that bad tank is bad, or the fault is on you as a healer for using one of your 2.5 second GCDs to heal someone other than the tank. Case closed.

You stand up for the game's "tactical nature." Then you paint a picture of the game's tactics forcing healers to endlessly overheal a single target with every 2.5s GCD just in case an emergency presents itself when they can't cast, because they can't count on being able react to an emergency by using instant-cast abilities off of the GCD. Spam healing a single target -- where exactly is the game's tactical nature that you mentioned?