Not the main reason MS "won" the day.
IBM may have gone with MS, but the real issue was down to Charlie Chaplin.
Back in the 70s, our OS had separate sections for code and data, and once loaded, the code could not be overwritten. Shame no one continued this simple solution. We also used to test the products before release!
However in the early 80s, there were a proliferation of good PCs about which ran DRDOS and CPM.
We used one to enable 4 users concurrent access to local computing for such things as word processing and also as remote terminals for our mainframe.
Then along came the very backward IBM PC with its simple OS, which was a mish mash of earlier OSs, which confused me slightly when they later started IPing the various bits such as disc format etc.
Meanwhile, I had been told back in the 70s that the US were rubbish at programming, but very good at Marketing and even now I have not really seen anything to contradict that generalisation, which leads us to the IBM PC.
IBM were the only computer company in the world according to a lot of Americans, so when IBM brought out their PC endorsed by Charlie Chaplin, well his character was in the ad!, the US businesses got behind it as they trusted Charlie and bought IBM PCs.
The PCs needed applications to run and that was where the difference lay.
The IBM OS was cheap, the IBM PCs were plentiful so developers concentrated on that platform.
Digital Research on the other hand were charging many times more for their OS, and with fewer units out there, unless there was a specified need, the developers either concentrated on the IBM PC or themselves charged the other arm and leg because of the multiple concurrent access etc.
When businesses decided to take the plunge, it was simpler and cheaper to go the IBM PC and compatibles route as there were already plenty of cheap applications about if they wished to expand later.
Unfortunately, the better PCs died off fairly rapidly condemning the IT sector to decades of floundering.