True. I personally have setup my distro to launch directly into gamescope optionally for SteamOS like experience. On desktop client they still either hook or us

True. I personally have setup my distro to launch directly into gamescope optionally for SteamOS like experience. On desktop client they still either hook or use vulkan layer (latter often in proton, thanks to dxvk). However I would not be surprised if they started using nested compositor even on desktop.