Linux as a desktop machine is horrible. Dozens of package managers, distros, UIs, everything. Instead of creating one thing right and bug-free, linux devs prefer to waste their time reinventing the wheel.
I still think the world of Linux desktop development is a total disaster, though. GNOME is out for blood, KDE is building great stuff on a terrible library, and everyone else is just shifting uncomfortably because Wayland still isn't desktop-agnostic (much less hardware-agnostic, for that matter). The way things are headed, I wouldn't be surprised if Linux was almost entirely unsupported by Slack/Spotify/Discord in 2025.
It is as if you are arguing that there should only be one motorized personal transportation device. No small or large cars, no trucks or motorcycles.
Different people have different needs.
and this to me is the biggest hinderance to its wide adoption. it caters to a specific crowd.