Valve's the main force here, AFAIK. I do think it'll make a big difference for home users. Home PC gaming, outside a handful of much-smaller niche use cases that're full of Windows-only software, was the only notable reason for a home user to have Windows at all, after the rise of Chromebooks and iPads to serve the rest of the home market. Valve's made ditching Windows for PC gaming viable for a high proportion of those remaining must-have-Windows users, which means Windows is hanging on to the home market by its fingernails. Just about all it has now is momentum, and that's fading.

I also don't think any of that matters much, because it's done nothing at all to the enterprise market, which is still full of Windows and other Microsoft stuff and that shows no sign of shifting.