As if you could not do that on another OS.

You can use Nvidia GPUs in SLI mode in Linux and BSD too. I am using an Nvidia GPU right now and I am not using Windows, and "everything just works" too, no terminals involved. Are you implying that it's not possible to do this outside Windows?

How much of that market capitalization comes from running a de-facto monopoly of office suites for decades? As a consumer, it's hard to see how corporations like Microsoft push governments around the world to buy licenses in bulk because there are no alternatives.