Just nope
The best O9S WHM DPS run pre echo
My solo heal of O9S, again pre echo
Despite the fact that Youmadesca's kill was a minute and a half quicker than mine, he got the same number of Assizes in whilst also getting significantly better value out of his full kit than I did.
It's not a case of focusing on DPS that prevents a healer from getting value out of their oGCDs and cooldowns. Rather, that simply comes with better standards of play as I hope my links demonstrate. I can link countless healers with sub 50% active rates in 24 man that literally do nothing outside of cast Medicas Its and Cures if you'd like me to further demonstrate my point =(
The problem with this view is that the game fundamentally wouldn't support a pure healing role for a multitude of reasons.
1) Casual content just doesn't require that much healing, it never has and it probably never will. Yoshida has demonstrated time and time again that he isn't willing to put pressure or responsibilities on healers. From ARR onwards we've only ever really lost facets of our gameplay with debuff rotations, buffs and dps complexity only ever being eroded.
2) Hardcore content doesn't require all that more healing either TBH. Yoshida's comments about leaning Savage more towards Creator difficulty (The easiest Savage tier yet) has me inclined to think this isn't going to change much either.
3) By gradually eroding healers side roles such as Virus chains. Our gameplay has pretty much turned into two sides of a coin. We can either be healing, we can be DPSing or we can stand there twiddling our thumbs. There is little else we can offer to our parties as things now stand.
These changes are absolutely not wedging us into a pure healing role. It will take sweeping changes to our toolkit as well as a big rethink on encounter design. Rather, they are simply diluting and simplifying a large chunk of our gameplay options.