[Arnavion]

I also have no citations, but Fedora and Ubuntu are each more popular than OpenSUSE, KDE Neon, Arch and Manjaro, so assuming that the same proportion of users of each distro stick with the default DE, it's probably true.

(Arch doesn't have a "default" DE, but https://pkgstats.archlinux.de/fun puts KDE at 36% and GNOME at 22%, so I put it in the KDE camp.)

[deafpolygon]

I'd wager that's because a vast majority of Arch users are power users and KDE has power-user features.

GNOME's number is buoyed by the numbers of Fedora and Ubuntu (since they use GNOME or variant as their 'default' DE).