Valve’s “fake Windows Linux device that just runs Windows games without paying Microsoft money – how is this not a violation of Windows TOS”

Valve uses a build of WINE called Proton, not Windows. Microsoft’s TOS terms apply to Windows. They don’t have anything to do with software that’s simply able to run the same binaries.

EDIT: Ah, I looked at your comment history, and it appears to just be trolling, so I assume that this wasn’t a serious question.