On one hand, the amount of fragmentation on desktop Linux is absurd. On Mac and Windows the desktop environment is synonymous with the operating system. On Linux, you can run one of 30 different desktop environments on the same distribution. This means that userspace bugs can manifest for any desktop-distro combination.
On the other hand, System76 is well positioned to create a desktop environment that is cohesive and complete since they’re trying to sell computers running them. Linus on the server has financial backing, and Linux on the desktop has precious little.