Many user have reported Photoshop is no longer detecting their GPU. Adobe changed GPU requirements for Photoshop 2021 and state that some older GPU are not longer supported or may have limited use. Adobe has change GPU support in every 22.x.x updated Adobe is have a implementing their new support.
On a Mac if you can install Device drivers try the latest Studio Device drivets Nvidia has for your display adapter. However I can not find any Mac Device Drivers on nvidia site. You may need to get drivers from Apple.
Thank you for the information. I haven't been able to find a way to manually update my graphics drivers on Mac. They seem to be tied in to the general Mac updates. If PS no longer supports my GPU, I wonder if updating a driver would help at all.