I have been using Linux for nearly 30 years now, including running CS (HL1) via Wine with better performance and stability than Windows 9x on a LAN party. Good times.
Sometimes native ports don't get updates, while Windows port does. If you can then run it via Wine, you may have a more stable/less buggy experience.
Note I use both Wine and Proton. BG3 I run with Proton. But Proton is 'just' a fork with (neat) improvements which also partly got backported.
Oh, and I have to mention, I don't use Arch Linux.
So if you force it to run on your Linux desktop you don't get an experience commensurate with your hardware.
[0] I still use Arch, btw. :)