This is a very interesting question with two answers. The short answer and the long answer.
The short answer is….
The stock market would be much different and many industries that depend on revenue from Windows and Mac/OS would not exist. Computers would be more secure and although there would still be some hacking into computer systems, it would be much less.
However bad that sounds, it simply would be a different parallel universe because….
The long answer is…
Bill Gates and his wife have done a lot of good in the world with all of their money. That wouldn’t have happened.
On the other hand, the whole idea of ransoming and monetizing an operating system is bad for a freedom seeking society.
Even now, all of the top 100 mainframe supercomputers in the world run Linux, not Windows or Mac/OS.
Windows is fading as the desktop computer fades (but will never completely go away). Now we have a lot of reliance on smartphones, tablets, smart TVs and consequently the cloud. Even so, although the Android operating system is in itself a Linux distro, it certainly has been monetized and ransomed in almost all major brands of phones, including Google who created the Android OS.
The conclusion is…
The world would be a little different, but there would be and always will be big fortune 500 companies making money one way or another off of operating systems.