Yes, you can technically get some games working. If you use the right VR headset (meaning Valve Index or Vive), use the right distro, with the right compositor and right GPU, spend a lot of time troubleshooting, then you can maybe get a few games to start. Camera passthrough won’t work, power management won’t work (no control for base stations), Bluetooth won’t work, tracking won’t be as good, you will experience weird bugs and crashes of both the games and SteamVR, and you will get less FPS than on Windows. And even with that inferior experience, most games still won’t run.
I spent a lot of time trying despite this being the experience for most people online, and I only confirmed that it’s the case. Windows is absolutely needed if you want a good experience. Hopefully Valve changes that in the future, but that’s the case today.
Sure, as I said “Windows is absolutely needed if you want a good experience”. Yes, it’s not required to get something working if you try hard enough, but it is required if you want everything to work well.
I keep a Windows virtual machine with GPU passthrough for VR and don’t see myself ditching it any time soon. At least I don’t need to boot into Windows.