A lot, actually.

BLM has little improvements to do, it's actually one of the best designed jobs.
DRG doesn't need much improvement, what I see the most is that claw&fang buff needs to be longer.
SAM feels very nice to play, there's some problems with the stacks and Double Midare timing (You need to be carefull and delay your Meikyo Shisui to be always lined with Tsubame gaeshi)
MCH needs a bit more depth, but it's a request from the community the job works fine. There's also Hypercharge and latencies issues, it needs a short clean-up but IMO, it's fine. Flamethrower and Wildfire falls in the "depth" problems.
SMN is a massive joke in my opinion. The pets, the disconnected rotation, it needs a massive rework. And you need to start from the pet.
RDM seems fine, the jobs could get a little more depth but it works just fine since Stormblood.

I can't speak for MNK, BRD, DNC and NIN.

The rest is about the ranged role as a whole, it works, as long as a car can get you from point A to point B within a reasonnable amount of time, it's functionnal and perfect for the current needs. Same principle for ranged, it's a wish that more is added to MCH/DNC/BRD but it won't kill the job if they don't.