So what is the desired state truly? Hypothetically if there is extra dps that can only be attained by "doing healer role well", I will leave that definition to all whom it concerns, that gets snitched from [The basic damage spell of each healer job] right? Because I doubt Unit 3 was healers as a role to do more dps than they are currently doing, taking away "damage market share" from the rest in the full party, dps checks staying zero sum. Overhealing leads to lack of slack, lack of slack leads to no time to dps. That would be like reallocation of dps behind a skill barrier. You could throw dice to predict if that would boost healing popularity or snub it further.

And considering the party sizes that are inherent to FFXIV, healers (just like tanks and DPS) are forever meant to be super interchangeable with each other so truly decisive unique specializations are not going to happen anymore, especially with Sage bringing the count to four.