For those struggling to run 4K at max settings FFXIV has two settings that add a ton to rendering overhead but have subtle, almost unnoticeable effects. The biggest offender is Transparent lighting quality. Turn this down from Max to Normal, personally I see nothing between the two settings besides some reduced lighting reflections from still water (pools, lakes). The second is Screen Space Ambient Occlusion, turn this down from HBAO+:Quality down to HBAO+:Standard. There is an ever so slight difference between Standard and Quality but its effect is subjective, SSAO shadows just intensify ever so slightly. Make sure to test outside of the main cities as most systems will be CPU bound there, especially older Skylake or Zen 1 based rigs and ofc anything older than those. In the Goblet at night (Lots of lighting and water) for instance, my baseline for Max preset on an RTX 3060 and R5 5600X @ 1440p Ultra Vsync off is 75fps, GPU load at 100%. Transparent lighting Quality from High to Normal takes it to 85fps, turning HBAO+from Quality to Standard takes it up to 95fps. That's a big jump for some extremely subtle effects.

As for DLSS 2.0 or FSR 2.0, that would be amazing if only to have modern temporal AA...