I'm running a 6900 XT with Arch after upgrading from an RTX 2080 Ti and let me tell you, AMD is just so much better under Linux than NVIDIA.
Probably didn't have the amd kms driver in the initcpio environment. Arch updates it when the linux package is installed/updated, and the regular init environment only includes drivers for installed hardware (unless you explicitly tell it to include something). The "fallback" includes everything, however.Found a Reddit thread where a few people had the same issue. I booted into recovery, ran sudo mkinitcpio -p linux, rebooted and all is fine now.
I may go to Ubuntu if Modo does not work, it did before in Mint so I expect it should again. Thanks