Whether files and bookmarks are shown is determined by a setting:
Application Menu Settings > General > Expand search to bookmarks, files and emails
Also, anything other than applications is displayed in separate columns. The applications column remain the main focus. So, adding the path to this alternative launcher layout too can only be a good thing for consistency and functionality.
KRunner doesn’t show the number of files and folders the launcher shows in its scrollable widnow. Insead, it shows all sorts of other information defined by the plugins. And it takes pressing two keys (I only press the Super key here for the launcher).
An additional idea might be being able to force KRunner to show only files/folders in a long list, possibly by starting the query with an ‘f’. But I will still prefer the launcher.