NIN is at least pretty fine how it is IMHO, and at most deserves to be nerfed ult-wise and tuned in some parts. It is literally a "Competent at all, Master at none" class that is designed to not be as boring as the other classes having binary buttons that provide everything they need in one go which I think is nice that it has. I do want to state, that as a Casual Only Player, who has played several upon several times against and as NIN, these feel like proper things to say.
  • Can casually be a ranged job for a short period, with pretty decent burst and consistent damage output, basically not needing to be stuck in the middle of brawls or erode at Ranged Classes resources potentially without even getting in super close range of them, let alone other Melees when most Melee's have long cooldown ranged options, or are designed to stick to targets.
  • NIN having all their Skills as an instant cast on the fly would be horrid to play against. Even if the counterplay window is microscopic, hearing a NIN pop their Three Mudra is indicative they're about to actually do something. Instead of just instantly stun chaining you or just laying out a Hyosho Ranryu almost instantly after using Dokumori, so I believe it deserves that little gap at current.
  • Being forced to pick from Offensive/Defensive is perfectly fine IMO, since Bunshin already applies a Barrier for a time so they do have a OFF/DEF ability already even if small. NIN has nuance compared to other classes, risk and reward and you gauge how much risk for how much reward.
  • Shukuchi Stealth is annoying I will say, for how short it is, but it surely works properly, and the fact you can literally warp with it to a location if you're timing is good enough and still retain stealth even if you were getting hit is extremely satisfying/annoying. NIN already has tools that make having a speedboost on Shukuchi cast either redundant or oppressive with their long range burst potential and LIMIT that is comically stupid to fight against. If you really want to go in fast to burst someone with Stealth, you gotta use a resource for it, and I think that's kind of neat that it isn't binary.

Mind you with all of this listed, I still miss Shadowbringers NIN and would rather play that than this current iteration just because of how stupid it was to screw with people in Frontline, but we're not in Shadowbringers are we?