3 less powerful abilities that take 3 GCD is how I look at it. I need to heal still, but 1 GCD to pop a nice big damage ability then back to healing is nice. It's not about a large number that is shiny to see, it's about the fact that it is an amount of damage that isn't insignificant and doesn't take 3 GCD which I could have just cast Holy or Glare for the same damage. It is balance in that it can only be used when you have a blood lily.
More off GCD heals are not really needed in my opinion. We have a basket of utility to instantly cast group heals already. Swift Cast --> any of our AE heals, Assize, Afflatus Rapture. Benediction for single target 180 second cool down full heal. Tetragrammaton instant heal.
Some things to do while waiting for GCD is hit Presence of Mind and Thin Air, then begin spamming Holy chains for stuns and AE damage. Hit Tetragrammaton for OGCD heal the tank and when needed, hit Afflatus for another instant tank heal, then either DPS more or heal more as needed. Another GCD? hit Lucid Dreaming.
30 seconds to wait for a lily is very reasonable and the only time I am ever out of them is at the beginning of a dungeon. Most tanks pull more than 1 group of trash, so Dia one and it will start your Lily generation while you're running to follow the tank to the trash kill spot. If it was less than 30 seconds for easy lily, you could be using Misery once a minute! That would be a bit overpowered as a healing class to me. I cast misery at least twice between each boss battle and usually 2 or more time during the boss battle. My lilies do not go to waste !
GCD need to exist or the game just becomes Final Fantasy button mash.