The one of these I'm conscious of is using the web browser's location bar as a quick text editing area, including pasting in to it then cutting out of it as a way to remove text formatting from something on the clipboard.
I don't think there's a sysadmin in existence who hasn't misused $(cat). It's really for concatenating 2 files, but only rarely have I ever used it or seen it used for anything other than quickly checking contents of a file; e.g., $(cat package.json | grep version).
I use apps. They may not always be used for their intended purpose but my use of them provides my desired result either more efficiently, conveniently or cheaply than other methods available to me.
I think all of us do so daily without even knowing about it.
