You are talking about the Linux kernel. Desktops (e.g. KDE, GNOME, Unity, etc) run practically exclusively on AMD64 systems that take the laptop or desktop for

You are talking about the Linux kernel. Desktops (e.g. KDE, GNOME, Unity, etc) run practically exclusively on AMD64 systems that take the laptop or desktop form factor. What we've seen are ill-fated attempts to make those desktops work well on touch devices. That's what Unity was all about. On the other hand Apple has refused to make macOS run on touch screens.