Microsoft does not have a monopoly on distributing software on Windows.
Hell, Apple itself does not have a monopoly on distributing software on MacOS.
Really, you could say the same about, AFAICT, every single major operating system that has ever existed, other than iOS.
> Microsoft does not have a monopoly on distributing software on Windows.
It's a different degree but both control who can effectively distribute software on their platforms to some extend. Google does at lot to make outside the app store a miserable experience and Microsoft has a nice protection racket where if you don't play by their rules and pay the fees your software might just get deleted from your customers systems.