The Kirigami HIG specifies mobile and desktop UIs for Kirigami ListItems: On Demand controls (https://community.kde.org/KDE_Visual_Design_Group/KirigamiHIG/CommandPatterns) "If the main task for a list is selecting an item, but users often perform "quick actions" on a single list item, use on-demand controls, which are shown on mouse-over in pointing device oriented interfaces, and via a "slide-to-reveal" handle in touch-based interfaces. " The Mobile "slide-to-reveal" UI has been implemented, but the desktop one hasn't. So desktop users of Kirigami apps like Discover see the mobile UI and are confused and irritated, and provide a steady stream of negative feedback :)
*** This bug has been marked as a duplicate of bug 364383 ***