This is 90% true, but also the 10% matters in terms of "onboarding people to the desktop," which I think still is very important (and actually going reasonably well, IMHO)

Right, but that's all taken care of. Chromebooks outsell everything else, and Android phones outsell everything else, and Steam Decks haven't quite got there yet but it's early days.

Linux is 100% of one market segment, broadband routers. No matter how staunch a Windows zealot someone is, there's a bunch of stuff they depend on that cannot be done with Windows at all, not no-how.