Earlier quoted context omitted.
Windows is a bizarre product at this point; it is what the company is famous for, but it is small beans next to Azure, right? Nobody would get into the Operating System business to make money I think, the going rate is $0, subsidized by something (an ad company, a hardware company, or general kindness and community spirit).
No, Windows still has Windows tax, which is why I always choose "No OS" when buying a machine. MacOS/iOS/iPadOS were never for sale separately, so we can't judge the price. Android sure is subsidized though.
Mac OS was though. OS X 10.0/10.1 were sold for $129 as an upgrade for Mac OS 9 users. Apple continued to offer OS X as a paid software product up to 10.5 or 10.6 (though it was also bundled with new Mac purchases).