What is the purpose of a movie? Well, you can name a few: to tell a story, to give a lesson, to send a message, to show you something you wouldn't get to see on a daily basis, to provoke a feeling, etc.. Some movies have more than one purpose, some other purposes are not listed here (of course).
Borgman fails. It fails in any purpose at all, unless the purpose is to make you think about the movie itself. It tells no story, at least not in the strict sense of "story", so it is not a drama. It has no moral at the end, so it is not a fable. It won't creep you that much (if you are used to watching horror movies, expect no chills and no jumpscares). There is no relief nor release at any point, things just happen and hang you in the expectation something significant will happen, but it never comes. You can't identify with any character at all, they are all too apathetic or simply too shallow for someone to have any sympathy for them.
The only thing Borgman made me think of is Borgman itself and I mean the movie, not the character. What is the point of making a movie? What is it's purpose? This movie apparently has none. Unless I am too stupid to understand anything, but (in my understanding) if you must have a PhD to understand/enjoy a movie, that movie failed.
The only thing Borgman made me feel is boredom. And regret. Maybe I'm too insensitive, maybe hours and hours of terrible horror movies made me too cold, but everything is so surreal that... "Nah, this would never happen" is the only thought I had in my mind throughout the entire experience (and I rate "Gerald's Game" 9 stars).
It deserves 3 stars for photography, make-up and direction. If you want to jump in, be my guest, but be warned: you'll regret the time you sit and watch this.