Why not? It works pretty well.
KDE is janky, and most of the rest are kind of limited in functionality. GNOME just works.
I actually switched to GNOME recently because Wayland works just fine with it and KDE seems to crash, despite me having an AMD GPU. I want it because I have two monitors with different refresh rates and one supports FreeSync, and GNOME Wayland handles it perfectly, whereas KDE doesn't even launch. I don't know of any other DE that would work well with my setup.
I don't particularly like GNOME, but it works well. I used KDE on openSUSE for >2 years now, and I always seemed to run into random bugs and whatnot. I switched to give it a shot after years of using GNOME on Arch, and now I switched back to GNOME on openSUSE and those janky problems went away.
I'd love for KDE to work well, it just gets in my way too much. GNOME just works, so I use it. Maybe I'll go back to a tiling WM (maybe Sway?) at some point, but since my kids use my computer, I'll probably put off doing that.