“You usually have to install the OS when you buy a computer. It is just done automatically.”
That’s simply not true. With factory-installed Windows, starting the PC for the first time does little more than selecting keyboard type, language type, timezone, PC name, starting the connections to the local area network, and building an initial login account. All of these are simply configuration items easily changed later on, with the exception of the language, which CAN be changed, though it basically takes a hack to do that.
Doing all of that is NOT “installing the OS” ...
The OS was installed at the factory prior to shipping. IOW, it was installed FOR you. It is that convenience that the Linux market place lacks, though it is possible with some vendors to have Linux installed instead of Windows. But that is a special request.
Actually it is. If you don’t believe it, don’t do it and just use the OS