Instead of one big GUI app in CLI you often supposed to use combination of smaller tools. When you know which tools you need you can read man pages for them. But it is not easy to discover which tool you need. Especially in Linux where you need install it first.

Other problem: man pages are too long to read because modern CLI tools are cluttered with lots of rarely used options. I wish developers followed Unix way [1], but trend goes in the opposite direction.

[1] http://harmful.cat-v.org/cat-v/unix_prog_design.pdf