The issue is the 128gb of memory. I have the same issue, 64gpu/128gb/4tb Mac Studio Ultra, and am relegated to playing FFXIV on an older, lesser equipped machine. It seems something in FFXIV's coding causes endless viewport frame buffers to occur in MacOS in systems with more than roughly 80gb memory. You can watch what happens with your memory if you open Apple's activity monitor and then try loading FFXIV. You'll see the game immediately take almost all of the memory, and either crash, or get stuck at the black screen you describe. Until the company that creates the Wine wrapper for the MacOS version finds a resolution for this, MacOS changes somehow, or we can pray Square makes a true M1 MacOS client, since it is the future of Apple, the game will not play on your, mine, or any other Mac with 128gb of memory. Do some online searching, you'll find a lot of articles/posts about it.
