I do use it, frequently. So frequently that I have designated Force Quit as my “turn it off and on again” mechanism for nearly everything for years. Granted my daily usage app catalogue is minimal, and I agree some aspects of normal behavior are less predictable than one might wish (the article covers those). So I respectfully defer to your experience and decision not to use it. In my experience it’s as reliable as Quit or Shutdown for every app I use, and sometimes more reliable for misbehaving apps which have custom state saving functionality. VSCode in particular comes to mind, it restores undo/redo history when force quit and falling back to built in system behavior but comes up with no history if I so much as agree to a software update.
> Honestly what is the benefit? A computer is off, on, or sleeping.
The benefit is that, excepting certain details most use cases rarely encounter, the computer and apps running on it have only one state instead of three: resume where you left off. For active multitasking, that means waiting for volatile storage. For “App Nap”, Force Quit, and crashes that means waiting for non-volatile storage. For reboots and logins that means waiting for a bunch of other apps and services to resume. But if the app uses the functionality even semi-faithfully, you’re only waiting for it to become responsive again, then it resumes as if it were in the same state you left it. Regardless of whether your computer or even your app was on, off, or sleeping.
Again, not saying it’ll work that way for you and I’ll defer to your experience. But if you want to know how other people benefit from it, my experience is I can kill almost any process on my computer or even force reboot, and the only consequence before I resume what I was working on is how long I might have to wait.