I fully agree that it shouldn't be possible, let alone be more efficient.
Going "but it's not what MOST players do anyway... and you need hyperskilled uber players anyway" is just moving goalposts, handwaving and not even true.
The AST solo heal in DSR was a case of praying to rngesus and using a specific class but we're still talking about the hardest content in the game, current ultimate AND the more difficult one - that gets solo-healed shortly after release before even having true Ultimate BiS.
And I've solo healed a bunch of savages and ex trials without issues... in PF. Nope, no hyperoptimized uberskilled world first static. Just PF peeps. And I still didn't have to dip into GCD healing most of the time. I've also seen my fair share of solo heal runs when I was on dps, e5s was good for solo healing as it only required one person to switch position for CL and that's it. Especially the weapon trials frequently got solo healed on my DC same as Zodiark Ex. Hydaelyn not as much but I still saw it. And Light DC isn't known for being the uberskilled pro raider DC.
1T/3D dungeon runs were done with casuals from my FC; players that were somewhere in the green area with dps, often not even playing their main class. How is that "excellent skill"?
There is no "everyone has to play flawlessly, perfect comp necessary, play rotation perfectly at all times, be perfectly coordinated" to pull it off except for DSR solo heal.
It is possible in all types of content, including the most difficult content in the entire game that SHOULD be designed around 2/2/4 but is somehow possible with 2/1/5. And for anything below savage, many PF parties can pull it off.
FFlogs blocked solo heal runs from showing up in the ranking but if they reverted that change, I can guarantee you that more people would go for solo heal runs.
The third party site is partly responsible for keeping the "ditch healers" in check. A third party site.