GrapheneOS is a Linux distribution similarly to the Android Open Source Project. Linux is a kernel and doesn't imply using glibc, systemd, GNOME and other software. The desktop Linux stack would go heavily against our privacy and security focus due to how dramatically far behind it is on those fronts.
@openrisk @jurgenhaas @smallcircles GrapheneOS is gaining desktop functionality including being able to run Windows and desktop Linux applications via hardware accelerated virtualization.