Microsoft has succeeded in imposing its OS pre-installation on the majority of personal computers sold. From then on, it became clear that the general public was not going to make the effort to install Linux.
In the past, the GUI on Linux was also much less user-friendly. Using the terminal was the norm.
Since the mid-2000s, with the emergence of KDE and Gnome, the progress made in terms of user-friendliness has been enormous.
Today, if you sell a personal computer with an Ubuntu distribution pre-installed, I think the user wouldn't even look elsewhere, to be honest.
So, it's more the marketing power side of Microsoft that makes the difference today. You will never have companies trying to come in and push for pre-installation of Linux distributions on personal computers.
From then on, Microsoft will continue to dominate this segment.