Weird/random idea for AST to make one ability actually...have a point:

[ForsakenRoe]

I guess it made the burst window and opener even more insane, so maybe that's why they changed it, but at least it had a PURPOSE.

MA's 'purpose' is that it allowed you to delete a card you did not want to play (for example, you have AOE Royal Road ready for a Balance/Spear/Arrow in a pinch, but you drew Bole/Spire/Ewer). Normally you'd be able to rightclick the buff off, or use a macro to remove the status, but with the shift to Job Gauges, Playstation/controller users lost access to that. Thus, Undraw was 'invented' as a pseudo-replacement to the macros they used to use. I say pseudo, because unlike the macro, which could be used not only mid animationlock but mid-cast of a spell, Undraw is a true OGCD and so has to be weaved, so the solution is clunkier than the 'janky workaround' we used originally. Classic. Anyway, with SHB changes, MA became the 'Undraw but better', and so UNdraw's existence became questionable, but it remained for some reason. Just like Freecure, I guess the devs either forgot, or they think it has some use that we're just not skilled enough to see.

Leaving things in the hands of "chaotic fate" shouldn't always be a net-positive, but we don't need to make solo and normal-mode content stupidly punishing, either.

Yes, I would agree, however, what we are seeing as 'net positive' is different from one another. Where you and Mint are looking at self-stat-downs and the like as the 'negative outcome', I'd see a lot of potential results from the 'use a random Job Skill' RNG machine as a 'negative outcome', not because it's effect is negative in itself, but because it's worse compared to just playing the card normally on yourself. Like, for example, if your only goal in that moment is 'do as much damage as possible', you have the choice of using the card on yourself for 6% more damage for 15 seconds, or you can risk it with the RNG machine. So while 6% on self would add up to, let's call it 5000 damage for ease of maths, not everything from the Undraw would result in 5000 damage. In my gear (bis except for weapon which is 645), I'd need a move with a potency of at least 130 to deal equal damage to what I'd get from just playing the card, and that doesn't factor in the Astrodyne Seal. So if I got, say, Fan Dance 2, I've lost damage because it's 100p. Bloodletter from BRD, 100p. Quite a few AOE combo starters are 100. A lot of skills don't even do damage at all, such as it randomly giving you pretty much any role action, or tank CD, or self-mit like Arcane Crest. Plus, I imagine it'd do the move as if you've executed it yourself as that job, ie, if it rolls Fan Dance 2 (self centered AOE) and you're in Narnia away from the enemy, you'd just use it out of range and miss, and lose the potency anyway, meaning that it's even more likely you lose damage

And lastly, there's still some truly negative effects (potentially). Gyoten/Yaten, Hell's Egress/the other one, Elusive Jump, Repelling Shot, En Avant, Thunderclap, Corps and Displacement would all be on the table as 'oops you got a bad roll, time to randomly flip off the edge/into the deathwall'. Nothing says 'chaotic fate' quite like suddenly being repositioned, unexpected Rescues in DF content show that pretty clearly

[MintnHoney]

And lastly, there's still some truly negative effects (potentially). Gyoten/Yaten, Hell's Egress/the other one, Elusive Jump, Repelling Shot, En Avant, Thunderclap, Corps and Displacement would all be on the table as 'oops you got a bad roll, time to randomly flip off the edge/into the deathwall'. Nothing says 'chaotic fate' quite like suddenly being repositioned, unexpected Rescues in DF content show that pretty clearly

Well, so that's where I would personally try to draw the line: any effect that would cause any player to be forced to move isn't just a truly negative effect, it actively stops playtime and potentially ruins the encounter (although I wouldn't avoid this so much in most other games, but in XIV, the extremely choreographed fights mean that unexpected forced movement is absolutely the worst thing you can do to someone). I think it would be better to avoid creating a scenario where the risks begin to severely outweigh all of the potential positive effects, because then Undraw would remain excluded from serious gameplay instead of at least considered for mixing up the now near-non-existent rotation.
Assuming the intent is to make Undraw a contender, but still give it random effects, I think applying status effects onto the party is about where we should cut that off, and even then, to avoid having players whine about ASTs being unplayable due to 1 skill being unpredictably good or bad, being able to Esuna all the negative effects off of players should be the answer to those situations where things go sour (and it'll give us a reason to have the ability on our bar at all times again, and we'll still feel the impact due to needing to spend GCDs removing the effects). If the issue then becomes "but the enrage timer!" because the healer(s) had to spend up to 8 GCDs on removing the effects, then that's probably more a skill issue and potentially a tuning issue for the encounter, and the alternative is to simply use the card rather than undraw if they must have reliability above all.