I would be very interested in hearing an answer to this, too, since I'm currently intending to upgrade to the 9070XT.

Unfortunately, since the 9070XT isn't publically launched yet (coming tomorrow), Square Enix probably hasn't had the opportunity to run any diagnostic tests on it.

Adding some context to OP's screenshot: The 9070XT usually trades blows with the RTX 5070Ti in most other games, so seeing it inexplicably lose by 25% in FFXIV 1440p (30% on FFXIV 4k) is disheartening.