Earlier quoted context omitted.
Recent release of the Windows 11 with requirements to have at least 8th gen CPU might help actually. My 6th gen is perfectly fine for a lot of games, and thanks to Valve I have quite a good library on Ubuntu.
Same was said for Vista, Windows 8, Windows 10 and probably many other times. Microsoft is not that stupid - they are doing these changes only after they are confident that they can get away with it and can easily change their strategy if needed.
I think that's somewhat the point of what Steam is doing. Positioning themselves to exist without MS in the worst case while applying pressure that may curb MS's most user hostile or competition-limiting (in the app ecosystem) initiatives. Especially at a time of chip shortages and price premiums, users are more likely to hesitate buying a new computer just to have the latest win version when their existing hardware is still fine.
I think this is especially the case with gamers where and older CPU is much less likely to be a bottleneck in performance.