I have heard from expert snipers that they actually make these calculations every time they need to take long-range shots
I didn't know that you know expert snipers.
A good eye is required to shoot anything, including at long -range, although a good eye by itself is never going to be enough, as you can see a lot goes into it. Also, forget what you see on movies, it's all rubbish made for entertainment purposes.
It's so cool that you have this technique as back up because, really, anything could cause you to be unable to use the rangefinder. And if that happen, you would just be rendered ineffective with your shots.
A decent long-range shooter is rarely totally ineffective as there's other ways to make shots count, data on previous engagements (DOPE) is one way, and if a shooter was operating in an area for a while would have the area ranged out fairly well from paper maps or GPS positioning; it's called preparation. There's more than one way to ensure rounds on targets and mil-ranging is just one of them.
Thanks for your comments.
Well yeah, actually. Filmmakers tend to exaggerate or over-simplify things in flms. I probably would be too nerdy to have the actual shooting process described in films. MRAD, range, circumference, you know... People would skip...
Yeah, people don't want to use their brains these days, preferring to get their information downloaded to them in the form of propaganda, and their thinking done for them.