I use KDE. Some use GNOME. Most other options are probably to be left out as X11 is unsafe.
Cosmic is not nearly finished, but will probably be a bit safer, as its in rust, even though not tested.
Then there are window managers like Sway, Hyprland, waymonad, wayfire, etc.
RaspberryPi also has their own Wayland Desktop.
Is every Wayland Desktop / WM equally safe, what are other variables here like language, features, control over permissions, etc?
Never heard of these jails, like bubblejail? Its available on Linux too.
I know the question is vague and highly dependend on Threat model etc. Pre-enabled services, distribution adding stuff to it, SELinux confined user (not working with Plasma at all), xwayland support for keylogging chosen keys (Plasma).
Also GTK is widely used for rust apps, this doesnt exist on Plasma at all, not a problem though as Plasma is not Gnome and simply supports GTK normally.
I don’t think the DE itself matters, but I can recommend using an immutable OS (makes it harder to install malware) and installing flatpak apps only. You can also use software like flatseal to further lock down permissions
I’m starting to think people misunderstand what an “immutable” distro really does…
Please do share with me what I do not understand.
A mostly read only filesystem built from a limited number of packages, with other files being in a fixed number of locations mean it is harder for malware to hide.