The idea is that you’ll go through the brain stem.

Which, it can. It just isn’t a guarantee.

But you gotta realize that movies, even ones that are meant to be mostly realistic, fudge that kind of stuff a lot. There’s insurance reasons even when they don’t care about showing it accurately, and most of the folks that work as the gun safety manager (can’t remember the right term for the job) will raise immortal hell if someone makes it too realistic. Well, the few I’ve talked to anyway.

As you surmised, “Tyler” missed on purpose. The narrator “Jack/Joe” is aiming at Tyler, it’s not meant to kill the body at all. Iirc, Tyler tended to be on that side of the narrator more often than not, so they picked that side. Can’t recall where I ran across that, though. Which is all tangential anyway.

But, putting a gun to your temple is pretty bad too. Just as likely to end up a vegetable. None of the positions used in movies are all that great if you want it to work, and that’s a good thing. It’s at least sometimes intentional, like how they fudge recipes for dangerous things (like they did in fight club) just enough that it won’t work right. They’ll give the big brush strokes to satisfy the chemistry nerds sometimes, but omit important steps.

It’s been ages since I researched suicide success rates (for a book, no bullshit, though I never used that part of my notes), but you never see the ones that are as close to 100% as it gets with firearms, or most OD/poison scenes either.

A lot of times the director and writers just don’t care about accuracy though. They just use tropes that are good on camera. Seriously, you’d be amazed at how much of most movies just hand wave as “good enough” because it’s what people think should be there. Like the “one phone call” thing when someone gets arrested, or not being able to file a missing persons report until however long they need it to be for the plot. I think screen rant did an article about that kind of thing a while back.

When it’s an action movie in particular, John Wick levels of almost realism isn’t the norm. It really is all about making it look good on screen, so don’t expect most of that stuff to hold up to someone that does whatever it is irl. It’s also common in books to do the research and still fudge things because reality gets in the way of telling a story sometimes. Which, again, tangential.

What isn’t tangential is that because people think that movies are realistic, they’ll do things the way it’s seen on screen. You ever get in a fight as a kid and someone was doing those stupid cowboy movie roundhouses? Great way to get knocked the fuck out because you’re wide open and not delivering power where it needs to be. But it looks great on screen.

Guns are no different. People do what they think will work, often because they don’t know better. But, in the internet age, they may think to look it up, but get worried they’ll get found out, or be “put on a list” (which is a trope of its own). So they just follow the on screen directions, and wake up without a face, or maybe don’t wake up and are hooked up instead.