Apple and Microsoft have a very different market share. Windows has something around 85-90% desktop/laptop market share. So you can make a very good argument th

Apple and Microsoft have a very different market share. Windows has something around 85-90% desktop/laptop market share. So you can make a very good argument that they have a functional monopoly over the desktop OS market. Contrast this with Apple, they have around 10% desktop/laptop market share and around 50% of the smartphone market share. Here you could only argue that they have a duopoly with google on the smartphone OS market. Microsoft had to open up the platform or they would have gotten destroyed by antitrust laws there and then. They had to let other developers deploy on their OS and support them because if they failed the government would have gotten involved and forced them. So smartly they decided let us no destroy the nice thing we have and play as nice as we have to to keep our profits and our market share. And they mostly succeeded in that regard.