For me it's mostly how most if not all jobs turned into a 2minute burst show overtime. I was fine with Machinist being the one that really wanted to shove their entire kit into their wildfire window as I had other job styles to play, now it's all the same.

So it's not necessarily the unique job gimmick each job has that feels samey (cause each job does have that lil flavor).
I'd just like to have that lil flavour of the job not just be 20% of their kit but it should be closer to 70% while the remaining 30% of the skills should be akin to role skills, ensureing that you have the basics covered to fullfull your role itself.
The personal high-level tank and healer skills are an excellent way to add flavor to the jobs (think Sheltron/Aquaveil etc)