Definitely one of the most malevolent possible objects. Infinitely black, so powerful it will kill you without noticing your presence, unknowable, impossible to get rid of, you will be well aware you can't escape as you fall in before it turns you into spaghetti Amigara Fault style. My understanding is from the outside you can even see the remains of previous victims being stretched and crushed in slow motion.

VR is fine when it's small cute bunnies or little golf balls that I can kind of immediately get a sense of scale for. Massive thing that tricks my brain like the edge of a gas giant is terrifying, no matter how much I tell myself it's just a screen or video or pixels.

I think it’s perfectly reasonable to have a word for this fear, but I agree that ‘phobia’ isn’t appropriate because (unless you’re worried about running into one on the way to the shops) it’s quite rational. ;)