Steam announced today that SteamVR is dropping support for macOS so the team can focus on Windows and Linux.
We recommend that macOS users continue to opt into the SteamVR [macos]branches for access to legacy builds.
Users can opt into a branch by right-clicking on SteamVR in Steam, and selecting Properties… -> Betas.
SteamVR first came to the Mac in 2017 when Apple added support for external GPUs. They’re most likely reacting to a lack of interest on the part of users and a lack of commitment on Apple’s part.
Check It Out: SteamVR Drops Support for Mac Customers