The CLI has many advantages over a gui. For one, actions are reific, repeatable, and scriptable. This saves time as you can reuse previous commands and edit them appropriately for the current situation. This makes it easy to look back and verify what you have done. The command line is also a much more stable interface. GUIs change all the time and it’s hard to remember where things might be located. The structure of a Unix system from the command line facilitates the discovery of installed commands/programs and documentation. You can record these actions once and repeat them on many machines. You can script common activities (eg bulk file renaming) that make file and data management easier.