The healing situation isn't getting unsustainable, it's been unsustainable since mid-ARR. I used to complain about it back then in my FCs, but after getting shouted down by people who just wanted fast dungeon runs I stopped bothering. I watched as they added more and more OGCD healing bloat, watching healers actually start talking about "DPS Uptime" unironically.

This isn't a new problem, it's always been like this. Things being a touch undertuned and the amount of raw cooldowns + OGCD healing available is just making the problem more easily evident. Green DPS should have died as a concept forever ago, but after everything from "Healers DPS in FF per lore!" to "just stfu I want dungeons to go faster.", my opinion is that players were willing and eager participants in making this bed and now they're going to have to sleep in it. We need an entire fundamental rework of what it means to heal in FFXIV, and it's not gonna happen in one patch or likely even in an entire xpac.