I think this is overselling it a little. I still run into issues with Proton from time to time that require sigkilling it and its children, and some games (especially EA titles) are finnicky and can take a few tries to launch properly.

As for VR, SteamVR on Linux outright sucks. It virtually never works the first time I launch it and requires some combination of reconnecting hardware and restarting software and the computer, and it's plagued with bugs (most recently the UI rendering upside down in the new beta).

Don't get me wrong, Linux has been my primary platform for some 5 years and my only one for the last few and I'd never dream of going back to Windows, and gaming on Linux has progressed unbelievably in the time I've been daily-driving it. But it still isn't totally painless and there's definitely more room for improvement in the coming years.