Gnome is the default on many important distro, but it is not flexible. A default DE has to fit to most people.
The way I see it, gnome is friendly enough to use that new users who don’t care about its flexibility will continue using it without issues while people who are bothered by the lack of flexibility are knowledgeable enough to change their DE or install a spin of the distro with their favourite DE
Most people just want a browser and a word processor plus simple spreadsheets once in a blue moon. For extremely simple and popular use cases many distros already work okayish OOTB, including those with GNOME DE.
While I absolutely don’t like GNOME and its design principles (prefer KDE), but I can see why it works for many people.
Now, for anything but the most popular use cases, that’s a whole different story altogether. I just spent the whole weekend installing and reinstalling every imaginable flavour or Arch and OpenSUSE and trying to get Hyprland or KDE to work on my NVIDIA gpu without issues and failing, then trying to stop my screen from flickering like a drowning sailor desperately trying to Morse code and SOS while on Alder Lake iGPU, and failed too. Two hours ago I wiped for what seemed like the 420th time and went crawling back to W11.
