MIME handling is DE-specific
There seem to be a weird behavior in xdg-open and xdg-mime: their codepath depends on XDG_CURRENT_DESKTOP and calls DE-specific binaries. Expected behavior seems to me is xdg-open/xdg-mime should be a reference implementation of https://gitlab.freedesktop.org/xdg/xdg-specs/-/blob/master/mime-apps/mime-apps-spec.xml, but the actual behavior is they call DE-specific binaries that sometimes don't follow XDG spec, but use their own custom ways to determine default application. This results in a difference with other XDG spec implementations (e.g. glib's GAppInfo), so different applications have a different behavior when opening URLs/files. This is annoying.