Not only would this break every fight in the game but people would complain constantly about their rotations being interrupted by having to dodge or not being able to dodge properly at all because of their 56k internet.
Would perhaps make more sense if we had more AOEs that would otherwise force melee combatants out of melee distance. Like if Pandemonium's Holy actually extended a fair bit further than max melee distance, as an example.
The mechanic is clearly better suited for melee combat or as a skillcheck against unavoidable AOEs (like line AOE charge attacks) that would hurt a whole lot more if not dodged. It's not bad per se, but the nuances would need to exist in such a way to not make it a direct DPS gain like Third Eye would on Samurai but rather act like an uptime tool similar to Arm's Length.
That said, limitation on what can and can't be dodged would need to be clear here.
On the one hand, I appreciate the experimentation in one-off encounters.
On the other hand, this version of "dodging" fell flat for me. There was no sense of urgency to it. There was no need for any sort of real awareness as to what was happening in the fight. I'm not even sure what it was I was actually supposed to be dodging. It was just, "ooh, unavoidable AoE, I wonder when the countdown will appear... <twiddle thumbs for a couple eternities>... 2... 1... Simon says to push the button!"
With a base GCD of 2.5 seconds, FFXIV seems to want to say (at least to me) that it follows in the tradition of turn-based RPGs. "Dodging" makes me think of action RPGs though. I don't really care which way FFXIV goes; I just want it to commit to one or the other.
It would be pretty bad to put on most jobs. But I think people are writing it off too fast. I think it would be a good thing to add with restrictions.
First and foremost, I could see this being a mechanic on one single job that is built around this mechanic in mind. That could be the job's gimmick like Mudras are for NIN.
It could be balanced in a way that it has a cooldown. It could be put on a job with an extremely short range of attack meaning that the job has to stick to the boss tightly requiring precision with dodges (this would be really high skill cap and not feasible for most FFXIV players lol). Following that, it could be a skill that requires you to be in melee range so you can't spam it if you disengage from the boss making it useless with mechanics that pull you away from the target. It could be only usable on things like orange AoEs on the ground, chariots, and basic raidwides and not set-piece mechanics like Party Synergy which is where the 'game breaking' would come from. It could be the only form of movement the job has, so the class wouldn't have any other tools to deal with getting out of AoEs. Add no dashes to the mix to reward foresight to saving a charge of it after a dodge where needed.
Maybe not all of these, but its the first thoughts that come to mind. Kinda sounds like it would be pretty hard to master, but the game needs jobs like that.
It could be essentially be a souped up backstep/teleport/shade shift - things that all melee have right now - and reward good usage with extra damage (like Third Eye).