I was just reading the German version of Techradar and they had an interesting article.
Mid and high end gaming displays sometimes have an option in the on-screen menu to put up a virtual cross-hairs over the displayed image (E.g. Gigabyte Aorus F127Q-X).
For games, like Rust, which don’t have a virtual cross-hairs displayed on the screen, it can be difficult to target properly and can make eliminating enemies in the distance hard. With the virtual cross-hairs, there is no more guessing about where the actual centre of the screen is.