While it is definitely not streamlined and very expensive, I've had a wonderful experience running a Windows VM and passing one of my GPUs through to it.
Even VR works flawlessly, which is otherwise unusable on a linux desktop.
Proton definitely still has major issues. A lot of the well-rated games on protondb are barely playable. Still, I've played a lot of games using it I otherwise wouldn't be able to experience.
>running a Windows VM and passing one of my GPUs through to it
This is very inconvenient because you have to install a new a GPU and then plug in antother monitor into th at new GPU.
>which is otherwise unusable
VR works nearly perfect for me. The main drawbacks is a broken video player in VRChat, no voice recognition in games that use Window's speech API, some anticheats not working, and that NVIDIA still hasn't added driver support needed for async reprojection. One final thing is that audio devices sometimes needed to be configured to the right device the first time you run some games, but from what I've heard from Windows users they have their own share of wrong speaker or microphone problems.
Hearing that VR works well with passthrough makes me want to try it again. I remember when I last tried it, everything worked great except for sound, which was staticky and choppy unless I handed the whole soundcard over to the VM.
Some setup is required, but KVM passing the system audio to pipewire-pulse worked first try for me actually. I'm normally using a virtual desktop to stream everything to my Oculus Quest 2, including audio, and it works surprisingly well.
