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).
Productivity and Cloud have a revenue of about 30B each while personal computing only was 13.5B (that includes windows Xbox and search + advertising) according to ms earnings report q4 25
If you want the "Home" version of Windows, you'll get ads and crap, but the cost will be free/low. If you don't want the ads and need a more professional setup, then you can pay for Windows "Pro" version. They also have server versions that cost a lot more, so yes, Microsoft can and does make money from their OS. No, it's probably not as much as they make from Azure now, but in the past it made them a lot of money. It's estimated Windows brings in ~$20 billion for Microsoft, which is nothing to balk at. Azure brings in ~$75 billion. $20 billion isn't "small beans" in this equation, it's substantial.
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.