kde-plasma/kio-extras installs .desktop file for ThumbCreator service type (/usr/share/kservicetypes5/thumbcreator.desktop). This service type is needed for thumbnail generations in Dolphin. Those of users who do not use sets, would benefit, I guess, if plasma-workspace (or plasma-desktop?) also RDEPEND on kde-plasma/kio-extras, because plasma uses ThumbCreator for generating image previews in desktop wallpaper setup dialog. Reproducible: Always
Thanks for reporting. This is fixed in git. cf7f0d307e9804dd21631a814cabac9ade692e84, 72f8947da643dfdf20d74ce0e625c620303dc072