I've been playing many kinds of mmo/online rpgs recently.

One thing I thought it would be great to have in xiv when I was playing Warframe and The First Descendant was Mastery system for each character/class/role.
I imagine something like current pvp season level/reward thing but for each job and you can rank up by doing any content as that job.

You get tomes, items(not sure what), and job specific rewards like titles,job themed mount, job specific emotes, cosmetics like portrait themes and I think they can tie artifact gear in there too like dyeable version or glowing version.
To me what xiv lacks alot compared to other mmos or live service rpgs is the sense of progression outside of your skill since we don't really have gearing or upgrades and the game is mostly skill based.

I understand that SE wants to keep it that way and avoid having hardcore content behind grind,so I think a global progression of you character and jobs that doesn't
give you power will be great.