“The idea that a Linux distro could never go mainstream is not true. It just has to be marketed correctly.”
Almost every website server out there is Linux. All the super computers and CERN are Linux. Whole countries run Linux as their government data system. Smart appliances all run Linux.
MS is nothing anymore compared to what runs Linux. Except desktops because people are lazy. Just too lazy to try it.
Android and (Apple's) OSX and iOS also are Linux. Android alone outsells all M$ OSs several times over.
The only market segment M$ still controls is desktops, and peak desktop was 11 years ago. M$ has completely missed the boat on handheld digital devices and 30-and-unders are increasingly less likely to need or want a desktop PC because they've grown up with a hand-held Linux computer at their side 24/7/365 and see no need for anything more.