Okay I can confirm that adding an eGPU solved the problem for me. My MacMini has integrated graphics and despite trying all the options and troubleshooting steps they gave me FFXIV Online will not run.

I bought a PowerColor Mini Pro RX570 8GB eGPU and it arrived today. The first thing I opened was FFXIV (nothing else running) and it started up just fine.

They cost just under $500 on Amazon WHICH IS STILL $500 TO MUCH THE GAME SHOULD WORK WIHOUT ME HAVING TO BUY ADDITIONAL HARDWARE!!!