Personally I haven’t heard of anyone getting support from Microsoft or finding Microsoft help pages useful. MacOS and Windows are making money on the support for corporate users and for manufacturers preinstalling the system (Apple being it for themselfs). Nothing that Linux cannot also do.
We are talking about going mainstream, then do you think that if Linux would have ~80% of the desktop market, there won’t be any commercial support companies and normie level help? There certanly is for the server space, even home servers like NAS devices.