SE treats the MacOS version of the game as if it were an entirely different platform like the PS4/PS5 even though in reality it's just the Windows client running inside a customized WINE skin. As such yes to play on MacOS you would need to buy everything again.


If you're running on an Intel-based Mac laptop, you could look into installing a boot camp partition for Windows and then using your existing FFXIV for Windows license to play once everything was installed. But if you're on M1 then your only option is to fork over the $60 to get a Mac license for ARR/HW/SB/ShB (though reports have been coming in that performance on M1 is pretty darn good despite not being officially supported).