The truth is, most people don't want to install operating systems, even if they're free and easier to install than Windows. The only way to go further is to ship with hardware and for that combination of hardware and software to be in demand. On top of that, when the operating system/desktop environment has reached a decent baseline of general usability like KDE Plasma and GNOME have, the software ecosystem around the OS/DE is more of a limiting factor than the UIs of the OS/DE.
The fact that System 76 sells laptops could actually give their DE a significant advantage over other small DEs if they ship their own DE. It's unlikely to overtake KDE and GNOME since System 76 doesn't sell tons of laptops like Dell or other big hardware companies, but I guess never say never.
I don't expect instant world domination, but I hope the Steam Deck (which will ship KDE Plasma for its desktop mode) will greatly boost the popularity and developer community of KDE. With success, there is a chance at a snowball effect where new users who enjoy the product contribute and bring attention, which brings more new users, etc. All things considered, the share of people using the Steam Deck isn't going to be that big compared to Windows or even MacOS, but it is getting a lot of attention.
One of my friends from the KDE community (which I am also a part of) has written multiple articles about this on his blog. Here's one: https://pointieststick.com/2021/12/09/what-desktop-linux-nee...
> A desktop environment isn't that difficult to make, that's why we have so many.
We actually don't have that many and they actually are pretty difficult to make. Linux has quite a lot of window managers, but not complete desktop environments. The 2 most popular ones require a lot of maintenance. Even GNOME, which has gained a bit of a reputation for dropping features is very large in scope.
A desktop environment is so much more, is a full stack development experience, with development tooling, APIs, and UI/UX workflows that users can be confident they work across most applications unless they go out of their way not to support the native idioms of the desktop environment being used.
Most of those "so many experiments" fail at being half as good GNOME/KDE are at being a full desktop environment as other desktop and mobile platforms are.
I don't know what else to say. I'm describing the landscape as I see it.
I do disagree that KDE or Gnome are stuck, I thought Gnome 40 was a nice refresh. It's evolved quite a bit from the Gnome 2 of Red Hat Linux that I used as a youngster.
A desktop environment isn't that difficult to make, that's why we have so many. Gnome and KDE peaked 10 years ago and they're now stuck in a local maxima, afraid to move outside their comfort zone. A new desktop environment is an opportunity to question assumptions and try to find a better design.