There really needs to be less downtime where the healers are only hitting their DPS buttons if they're insistent on not adding any actual depth to their offensive rotations.
Routinely having sources of damage other then predictable tankbusters and raidwides would help reduce monotony. A11S is a good example of a fight that has such in the form of the persistent fire DoT after Eternal Darkness and the prey marker Hawk Blaster that requires focused healing on the target.
They promised they'd "give us more to heal" in EW, but that never actually happened in reality and they mostly just made the incoming damage slightly higher which is offset by just hitting an additional cooldown and/or heal before going back to 1 spam.