It's possible that if people understand how to move on all the different mechanics, perhaps that bit of increased up-time would hedge the fight more into doable territory. I've been doing it more on tank now and a lot of things are sort of clicking into place as to why certain groups of people just can't pass that fight.
1) They do not understand the significance of positioning on hands of hell in the earlier phases. The person who gets targeted by the real ifrit needs to keep him closer to the group than the other players, and they other players need to keep dps up as long as possible and not just run away with the tethers. I actually caught onto this aspect early on in the attempts.
2) DPS needs to keep DPSing during the meteor strike combo. The issue is the mechanic makes it so that you do not want to be near the tank, as getting hit by any of the techniques will KO a dps instantly. The Tanks need to make sure ifrit isn't flying across the room when he goes at the tethered tank and then back to the other tank who eats the tank buster.
3) Again, players who are stuck are not doing enough research and practice to get through the mechanics before and after conflag. There's even nuances like where a tank should stand for the fire tornadoes, as well as a few tricks to saving valuable cooldowns for healers who are going to get hard pressed.
I'm going to be blunt, if people had DPS meters active in game to show their output, it would probably make this fight far easier to figure out and pass. The issue is that the devs didn't give those tools to players because they are worried about toxicity from their use. I mean, how do you tell someone that their few extra points of damage count on a phase when the drop seems unnoticeable until the enrage? The devs made mechanics that tell people to do the opposite of what they are supposed to do in a sense.