15 or so years ago, Microsoft started making moves in that direction and Valve immediately started trying to build and sell Linux based gaming machines in order to try and protect themselves somewhat from Microsoft. Those Linux gaming machines (Steam Machines 1.0) were a massive failure because they were expensive, and had very very limited game support.
Valve then spent around a decade improving Wine, building Proton, and designing the SteamDeck, which was a great success for them and is now making lots of people take Linux seriously for gaming. Now they're moving up the value chain and trying to make Linux the go-to place for PC gaming.
They've still got a big battle ahead of them, but already Linux users are around 4% of active Steam users, and the Linux experience is rapidly improving. Meanwhile, Microsoft seems to be bleeding goodwill, and is actively pissing off a huge amount of their Windows audience while simultaneously giving up on Xbox, so this is really perfect timing for Valve now.
That's not true. In the 2025 SO survey, both Windows is the most used OS for developers, for both professional and for personal use.
https://survey.stackoverflow.co/2024/technology#1-operating-...