Which Linux command or utility is simple, powerful, and surprisingly unknown to many people or used less often?
This could be a command or a piece of software or an application.
For example I’m surprised to find that many people are unaware of Caddy, a very simple web server that can make setting up a reverse proxy incredibly easy.
Another example is fzf. Many people overlook this, a fast command-line fuzzy finder. It’s versatile for searching files, directories, or even shell history with minimal effort.
For the average user you’re definitely right, but I will say for the sysadmin of headless systems, having a powerful cli editor is a godsend. While it may seem arcane and unnecessary, learning vim is easier than managing remote x or sshfs or copying files to and from a system.
I didn’t learn vim to be a contrarian; I learned it because it seemed (and still seems to be) the path of least resistance for many workflows.
I learned vi so I would not have to use ed or emacs!