Quick one: If on hyprland (or likely any non-plasma WM/DE), krunner is likely to not be showing installed desktop applications. This is caused by a missing symlink in the /etc/xdk/menus directory.

Easy copy-paste fix:

sudo ln -s /etc/xdg/menus/plasma-applications.menu /etc/xdg/menus/applications.menu
sudo update-desktop-database -v

This rebuilds the cache and allows krunner to see the missing applications :3