You can buy computers without an operating system installed on it

AFAIR that hasn’t been the case in most places for a while precisely because Microsoft made partnerships with OEMs to avoid that situation.

I believe new laws were added, e.g. in Europe, but I would be curious were this was the case. In fact I remember the opposite, namely that most computers one would buy always came with an OS, Windows for PC and MacOS for Apple computers. Even computers that one would buy in part that would be assembled for them from non OEM would also have the options to have an OS. In fact I’d be curious about example of fully assemble PCs, not just parts, that could be purchased without an OS before the law in the places where its the case now, would prove an OS-free option. Can you please share examples?