The problem with Linux desktop is that there is no such thing as Linux desktop, because Linux is not an operating system, it is just a kernel.
Unfortunately, instead of treat each Linux distribution as a different operating system, people think of Linux distributions as a single operating system with different package managers and wallpapers.
And this is the real problem: how people set their expectations.
As people think about Linux distributions as a single operating system, they expect they work exactly like Windows or Mac OS, when things work different, they point theses differences as problems, but I guarantee you, everything is working as intended.
People need to understand how the Linux ecosystem works and when they do, everything makes sense.
First, the kernel Linux is not developed to be used on desktops. It can be used, but companies pay Linus Torvalds to build the kernel for servers and other use cases, desktop is a side effect.
Second, the stack that is used to build a Linux distribution for desktops, from systemd to x/wayland to gtk to gnome, is primarily developed by a single company, Red Hat.
For the last 20 years, Red Hat is paying directly or indirectly developers to work on software that is part of Linux Desktop stack, but as you know, Red Hat clients are not people, they are businesses.
So what people call "Linux Desktop" is a set of loosely coupled parts primarily paid by a single company to satisfy their clients needs. You look to "Linux Desktop" as "Corporate Linux Desktop" all problems of "Linux Desktop" suddenly disappear.
"Linux Desktop" usually needs a technical person to be maintained, but it is just fine for corporate desktops, because corporate desktops are maintained by IT people, not by users.
"Linux Desktop" sound stack and graphic stack suck, but that is fine too, because the latest Nvidia graphic card that you want to play your favorite games are not needed by corporate desktop office users.
And about "Linux Desktop" fragmentation, people need to understand the myriad of desktop environments and applications are not "fragmentation", because there is no unified effort to build a "Linux Desktop", there is a myriad of independent developers working alone or with each other to build software that satisfies their own needs.
At the end of day, what people call "Linux Desktop" is just a side effect of different companies and developers building stuff for their own needs. The regular Windows gamer or your mom/dad are not included in the package.