Healer's barely have to heal.
FF14 healing damage mechanic is essentially:
Full HP
80% Hp
Near death
Dead

Most raidwides in high end content will put everyone near death, spam your group heal oGCD and you're done, back spamming 1 until the next raidwide or tank buster.

Either fight design changes so healers actually have to heal the way DPS have to work on their DPS, or they get more satisfying damage rotations.