I think I may know the issue now....just maybe in my case.
Try this and see if it goes same way as my
*This is not a fix the issue, but to test on varieties of PCs if my curious is true or not

I just recently change from GTX 1080 to RTX 3080 (from my brother, he upgrade his GPU) the issue is still there. but one thing that I noticed from my last post here.
Maybe the issue is tied to Unfamiliar framerate numbers.

In Display Setting > Frame rate (most down option)
this is where we limited our framerate cap, for gameplay we use on, None (Uncapped), 30FPS, 60FPS and Main Monitor Refresh Rate
Most games nowaday, have both Framerate cap, and VSync, correct? Some may use Framerate cap but not use Vsync because it increases input lag. I used it every games if that game included in the setting, because i dont want to force my GPU and CPU further than my monitor refresh rate. But if no framerate cap option, I will use Vsync to limt framerate even I have to play with high input lag.

In FF14, there is no Vsync, Our only option is; Main Monitor Refresh Rate at Framerate option. Game will sync your FPS number tied to you monitor. and that where is come the issue.

In Reality, there is so much variety of Refresh Rate Monitor hz, but Standard are; Commons, 60hz 120hz 144hz.......Esport level; 240hz 360hz 480hz and more
With these numbers in mind, other than these numbers are uncommon and unfamiliar to many developers. Like myself, I use Dell SE2717H/HX, 60hz Monitor but.....my Monitor can OC up to 75hz(74.95hz) my framerate can up to 75FPS as native as well. this number 75 is umcommon even some of you may not recognized and never heard it before.

Sound weird I know, but when I cap the framerate setting down to 60FPS. the stuttering seems gone. Yes the game look worse and not smooth with lower fps from monitor native setting, but it no sign of stuttering at all. I still see some frametime dip, but it's so minimal and unnoticable during i run around where I tested (Tuliyollal)